JP2021166289A - Adhesive sheet, laminate using adhesive sheet, and method for manufacturing the same, and method for manufacturing article - Google Patents

Abstract

To provide an adhesive sheet which can be bonded without being restricted by light transmittance and heat resistance of an adhesive body, has high following adhesion to an adhesive surface, and can suppress generation of burrs and peeling from the adhesive surface in dicing processing, and to provide a laminate using the adhesive sheet, a method for manufacturing the adhesive sheet, and a method for manufacturing an article.SOLUTION: The invention provides an adhesive sheet which includes an adhesive layer including: photocurable resin (A) having a polymerizable functional group other than a polymerizable unsaturated double bond; thermoplastic resin (B) having a polymerizable functional group other than a polymerizable unsaturated double bond; a photopolymerization initiator (C); and a filler (D), where content of the filler in the adhesive layer is within a predetermined range.SELECTED DRAWING: None

Description

The present invention relates to an adhesive sheet that can be suitably used for bonding members constituting the laminated body in a laminated body to be diced.

In recent years, with the miniaturization of electronic devices, parts mounted on electronic devices such as semiconductor chips have been miniaturized so that they can be mounted at high density. Since the work of small parts is complicated if they are manufactured individually, a multifaceted body in which parts such as semiconductor elements are multifaceted on a single substrate is manufactured, and the multifaceted body is individually diced (cut). By unifying, it is manufactured in large quantities at one time.

As a method for joining members, there is a method using a paste-type adhesive (see Patent Document 1). However, the application of paste-type adhesives is limited because it is necessary to adjust the thickness and control the coating amount at the time of application, and a cleaning process is required after application, and cleaning is not possible depending on the type of member. It ends up.

On the other hand, as a joining method instead of an adhesive, there is a method of joining members using an adhesive sheet (see Patent Document 2). According to this method, for example, one member (first member) can be attached to one side of an adhesive sheet having a desired thickness, and a plurality of members (second member) can be attached to the other surface. Since the distance between the first member and the plurality of second members is uniquely determined by the thickness of the adhesive sheet, the thickness can be easily adjusted, and the coating amount and cleaning are not required, so that the joining work can be performed. It can be simplified.

Japanese Unexamined Patent Publication No. 2003-136677 Japanese Unexamined Patent Publication No. 2015-120773

However, when joining members to each other using a photocurable adhesive sheet, the members are brought into contact with the adhesive sheet in advance to prepare a laminated body before irradiating with light, and the laminated body is irradiated with light through the members. It is necessary to proceed with the curing reaction of the adhesive sheet. However, in order to irradiate the adhesive sheet with sufficient light to cause a curing reaction, the light transmission of the member is required. For example, a metal member or a member on which a metal part is placed is made of metal. Since the member having a surface has low light transmission or does not transmit light, it is difficult to join by the above-mentioned method. Similarly, when joining members to each other using a thermosetting adhesive sheet, it is necessary to heat and pressurize at a high temperature in order to allow the curing reaction to proceed sufficiently, but this method has low heat resistance. It cannot be applied to joining members, and heating or pressurizing causes thermal deterioration, damage, or functional deterioration of members or parts. Further, there are problems such as distortion and deformation between the members due to the difference in thermal expansion of each member, cracks between the adhesive sheet and the members, and peeling.

Further, in the manufacture of a multi-faceted body, in order to firmly join the members, the adhesive sheet is required to have a follow-up adhesion to the adherend surface of the member, but the photocurable type or thermosetting type adhesive sheet is irradiated with light. Since the curing proceeds rapidly immediately after heating or heating, the flexibility is impaired in a short time, and the follow-up adhesion to the adherend surface having a step is particularly deteriorated. Therefore, during the dicing process, the adhesive sheet is likely to come off from the adherend surface of the member. On the other hand, if the flexibility of the adhesive sheet before and after curing is made too high in order to improve the follow-up adhesion to the adherend surface, the adhesive layer cured during the dicing process is softened by frictional heat and burrs are likely to occur. Therefore, in the small parts obtained by the dicing process, there is a problem that the joining force between the members is lowered and the performance of the parts is lowered due to burrs.

The present disclosure has been made in view of the above problems, and can be joined without being limited by the light transmittance and heat resistance of the adherend, has high follow-up adhesion to the adherend surface, and has burrs in the dicing process. Provided are an adhesive sheet capable of suppressing generation and peeling from an adherend surface, a laminate using the adhesive sheet, a method for producing the same, and a method for producing an article.

The present invention comprises a photocurable resin (A) having a polymerizable functional group other than the polymerizable unsaturated double bond and a thermoplastic resin (B) having a polymerizable functional group other than the polymerizable unsaturated double bond. An adhesive sheet comprising an adhesive layer containing a photopolymerization initiator (C) and a filler (D), wherein the content of the filler in the adhesive layer is 5% by mass or more and 45% by mass or less. offer.

Further, in the present invention, the above-mentioned adhesive sheet, the first member bonded to the first main surface of the adhesive sheet, and the second member bonded to the second main surface of the adhesive sheet. And, to provide a laminate having.

Further, the present invention is a method for manufacturing a laminated body using the above-mentioned adhesive sheet, in which a step [1] of attaching a first member to a first main surface of the above-mentioned adhesive sheet and a first step of the above-mentioned adhesive sheet. It has a step [2] of adhering a second member to the main surface of No. 2 and a step [3] of curing the adhesive layer of the adhesive sheet, and further before or before the step [1] or above. Provided is a method for producing a laminate having a step of irradiating the first main surface or the second main surface of the adhesive sheet with active energy rays between the step [1] and the step [2]. do.

Further, the present invention is a method for manufacturing an article using the above-mentioned adhesive sheet, in which a step [1] of attaching a first member to a first main surface of the above-mentioned adhesive sheet and a second step of the above-mentioned adhesive sheet. A step of attaching the second member to the main surface of the above-mentioned material [2], a step of curing the adhesive layer of the adhesive sheet to form a laminate [3], and a step of cutting the laminate to form a plurality of articles. The first main surface of the adhesive sheet is further provided with a step [4] of individualizing into pieces, and further before the step [1], or during the steps [1] and [2]. Alternatively, the present invention provides a method for producing an article, which comprises a step of irradiating the second main surface with active energy rays.

According to the present invention, bonding is possible without being limited by the light transmission and heat resistance of the adherend, the follow-up adhesion to the adherend surface is high, and burrs and peeling from the adherend surface during dicing are prevented. It is possible to provide an adhesive sheet that can be suppressed, a laminate using the same, a method for producing the same, and a method for producing an article.

Hereinafter, the adhesive sheet of the present invention, a laminate using the adhesive sheet, a method for producing the same, and a method for producing an article will be described.

1. 1. Adhesive sheet The adhesive sheet of the present invention is a photocurable resin (A) having a polymerizable functional group other than the polymerizable unsaturated double bond, and a thermoplastic having a polymerizable functional group other than the polymerizable unsaturated double bond. An adhesive layer containing a resin (B), a photopolymerization initiator (C), and a filler (D) is provided, and the content of the filler (D) in the adhesive layer is within a predetermined range. ..

The adhesive sheet of the present invention can be joined without being limited by the light transmission and heat resistance of the adherend, has high follow-up adhesion to the adherend surface, and causes burrs in the dicing process and peels off from the adherend surface. Can be suppressed.

More specifically, in the adhesive sheet of the present invention, since the adhesive layer contains a desired component, the curing reaction rate after light irradiation is slow, and the reaction gradually proceeds. Therefore, in the adhesive sheet of the present invention, when joining the members, light is irradiated in advance to cause a curing reaction of the adhesive layer, so that the members are bonded before the curing reaction is completed. Can be done. As a result, unlike a normal photocurable or thermosetting adhesive sheet, the members to be bonded are laminated via the adhesive sheet, and the curing reaction is performed without irradiating light or heating and pressurizing at a high temperature. Therefore, the members can be easily and firmly bonded to each other without being limited by the light transmission and heat resistance of the adherend.

Further, the adhesive sheet of the present invention can have flexibility even after light irradiation because the curing reaction does not proceed rapidly after light irradiation but gradually progresses because the adhesive layer contains a desired component. Therefore, the adhesive sheet of the present invention can follow and adhere to the adherend surface, particularly the step of the adherend surface in the process of curing the adhesive layer, and further has appropriate flexibility even after curing. Therefore, it is possible to show a high adhesive force to the member.

Further, since the adhesive layer of the present invention has a composition containing a desired amount of filler, the present invention has an appropriate flexibility even after curing to ensure adhesion to the adherend surface. When a laminate formed by joining members via an adhesive sheet of No. 1 is diced into pieces, the cured adhesive layer that has received frictional heat is prevented from stretching due to softening, making it easier to break. Can be done. As a result, it is possible to suppress the generation of burrs and peeling from the adherend surface, and it is possible to manufacture an article in which the bonding force between the members is high and the performance deterioration due to burrs is suppressed.

Hereinafter, each configuration of the adhesive sheet of the present invention will be described.

(1) Adhesive layer The adhesive layer in the present invention is a photocurable resin (A) having a polymerizable functional group other than the polymerizable unsaturated double bond, and a polymerizable functional other than the polymerizable unsaturated double bond. It contains a thermoplastic resin (B) having a group, a photopolymerization initiator (C), and a filler (D), and the content of the filler (D) is within a predetermined range.

The adhesive layer in the present invention contains a photocurable resin (A) and a thermoplastic resin (B), and each of these resins has a polymerizable functional group other than a polymerizable unsaturated double bond. Then, when the adhesive layer is irradiated with light, the polymerizable functional groups of the photocurable resin (A) and the thermoplastic resin (B) are activated, and the curing proceeds in a state where the reactivity is enhanced. Therefore, in the adhesive layer, the rapid curing reaction after light irradiation is suppressed, the curing reaction can be gradually advanced, and the curing reaction after light irradiation gradually proceeds, so that the light irradiation It can be flexible even after that, and the members can be joined. That is, the adhesive layer in the present invention is a delayed curing type adhesive layer. Further, the adhesive layer in the present invention can have appropriate flexibility even after curing.

The adhesive layer in the present invention is a photocurable resin (A) having a polymerizable functional group other than the polymerizable unsaturated double bond and a thermoplastic resin having a polymerizable functional group other than the polymerizable unsaturated double bond. It is a layer composed of (B), a photopolymerization initiator (C), a catcher (D), and an adhesive composition containing the same. That is, the total amount of the adhesive layer means the total amount of the adhesive composition constituting the adhesive layer, and the content in the adhesive layer is the content of the adhesive composition constituting the adhesive layer. It refers to the content in the total amount. It is assumed that the total amount of the adhesive composition does not contain a solvent.

<Photocurable resin (A)>
The photocurable resin (A) has a polymerizable functional group other than the polymerizable unsaturated double bond. Since the adhesive layer in the present invention contains the photocurable resin (A), the polymerizable functional group of the photocurable resin (A) causes polymerization by light irradiation, and even in a dark reaction or at a low temperature. Since the polymerization proceeds, the members can be joined without being limited by the light transmittance and heat resistance of the members.

Examples of the photocurable resin (A) include photopolymerizable compounds such as photoradical polymerizable compounds, photocationic polymerizable compounds, and photoanionic polymerizable compounds. Among them, photocationic polymerizable compounds and / or photoanionic compounds. Polymerizable compounds are preferred. In other words, it is preferable that the photocurable resin (A) has a photocationically polymerizable functional group and / or a photoanionic polymerizable functional group as a polymerizable functional group other than the polymerizable unsaturated double bond. .. When the adhesive layer contains a polymerizable compound having these functional groups, it is less likely to be hindered by oxygen during curing, and the continuous reaction easily proceeds even after light irradiation. Therefore, the light transmission and heat resistance of the member are increased. This is because the members can be joined without being restricted by sex. In particular, a photocationically polymerizable compound is more preferable because it has excellent reactivity after light irradiation and high bondability after curing can be easily obtained. The above photopolymerizable compound may be used alone or in combination.

The photocationically polymerizable compound is not particularly limited as long as it has one or more photocationically polymerizable functional groups in one molecule. The photocationically polymerizable compound has one or more photocationically polymerizable functional groups such as an epoxy group, an oxetanyl group, a hydroxyl group, a vinyl ether group, an episulfide group, an ethyleneimine group and an oxazoline group in one molecule. Is preferable. Above all, in order to obtain high curability and bondability after curing, the photocationic polymerizable compound is more preferably one having an epoxy group or an oxetanyl group.

As the photocationic polymerizable compound having an epoxy group, a compound having one or more epoxy groups in one molecule can be used. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, isocyanate-modified epoxy resin, 10- (2,5-dihydroxyphenyl) ) -9,10-Dihydro 9-oxa-10-phosphophenanthrene-10-oxide-modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, hexanediol type epoxy resin, triphenylmethane type epoxy resin, tetra Phenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed Novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, biphenyl modified novolac type epoxy resin, trimethylolpropane type epoxy resin, alicyclic epoxy resin, acrylic resin having epoxy group, polyurethane having epoxy group A resin, a polyester resin having an epoxy group, an epoxy resin having flexibility, and the like can be used.

Among them, it is preferable to use at least one of the alicyclic epoxy resin and the polyfunctional aliphatic epoxy resin, and it is more preferable to use the alicyclic epoxy resin. Since these are excellent in photocationic polymerizable properties, it is possible to obtain an adhesive sheet having excellent curability, and it is possible to impart a suitable elastic modulus for suppressing deformation of the adhesive layer over time after bonding. can.

The epoxy resin may be a modified product. This is because the flexibility of the adhesive layer and the adhesive force and the bending force can be improved by blending or adding other resin components to the epoxy resin. Examples of such a modified product include a CTBN (terminal carboxyl group-containing butadiene-acrylonitrile rubber) modified epoxy resin; an epoxy resin in which various rubbers such as acrylic rubber, NBR, SBR, butyl rubber, and isoprene rubber are resin-dispersed; as described above. An epoxy resin modified with a liquid rubber; an epoxy resin obtained by adding various resins such as acrylic, urethane, urea, polyester, and styrene; a chelate-modified epoxy resin; a polyol-modified epoxy resin and the like can be used.

On the other hand, examples of the photocationically polymerizable compound having an oxetaneyl group include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and 1,4-bis [(3-methyl-3-oxetanylmethoxy) methyl]. ) Methyl] benzene, 3-methyl-3-glycidyl oxetane, 3-ethyl-3-glycidyl oxetane, 3-methyl-3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, di {1-ethyl (3) -Oxetaneyl)} Oxetane compounds such as methyl ether can be mentioned.

Further, as the photocurable resin (A), it is preferable to use a photocurable resin (a1) having a temperature (Tg-Tanδ) at which the maximum loss tangent after curing is 100 ° C. or higher. This is because high heat resistance can be imparted to the cured adhesive sheet. Among them, the photocurable resin (a1) preferably has a temperature at which the maximum value of the loss tangent after curing is 105 ° C. or higher, 110 ° C. or higher, 115 ° C. or higher, and the above temperature is 250 ° C. or lower, particularly. It is preferably 230 ° C. or lower and 200 ° C. or lower. The temperature (Tg-Tanδ) at which the loss tangent after curing of the photocurable resin (a1) shows the maximum value is a dynamic viscoelasticity measuring device for a cured product obtained by curing the photocurable resin (a1) alone. It is a value measured at a frequency of 1.0 Hz using (manufactured by Leometrics, trade name: RSA-II).

As the photocurable resin (a1) having a temperature (Tg-Tanδ) at which the maximum loss tangent after curing is 100 ° C. or higher, for example, an epoxy resin solid at room temperature (hereinafter referred to as a room temperature solid epoxy resin) is used. Can be mentioned. The normal temperature means 25 ° C.

Specific examples of the room temperature solid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, and isocyanate modified epoxy resin, 10- (2). , 5-Dihydroxyphenyl) -9,10-dihydro 9-oxa-10-phosphophenanthrene-10-oxide-modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, hexanediol type epoxy resin, triphenylmethane Type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, Examples thereof include naphthol-cresol co-condensed novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, and biphenyl modified novolak type epoxy resin.

When the photocurable resin (A) is an epoxy resin, it is preferable to use an epoxy resin solid at room temperature and an epoxy resin liquid at room temperature (hereinafter referred to as room temperature liquid epoxy resin) in combination. That is, it is preferable that the photocurable resin (A) contained in the adhesive layer in the present invention is one kind or two or more kinds of normal temperature solid epoxy resin, and one kind or two or more kinds of normal temperature liquid epoxy resin. This is because by using the room temperature solid epoxy resin and the room temperature liquid epoxy resin in combination, it is easy to process the sheet into a sheet shape, and it is possible to impart an appropriate adhesiveness to the sheet before curing and it is easy to adhere to the adherend. Further, by using the normal temperature solid epoxy resin and the normal temperature liquid epoxy resin in combination, it is possible to obtain excellent adhesive reliability after curing. Further, by using a polyfunctional epoxy resin such as a novolak type epoxy resin as a room temperature solid epoxy resin in combination with a room temperature liquid epoxy resin, it is possible to obtain excellent adhesiveness at a higher temperature.

Specific examples of the room temperature liquid epoxy resin include a trimethylolpropane type epoxy resin, an alicyclic epoxy resin, an acrylic resin having an epoxy group, a polyurethane resin having an epoxy group, and a polyester resin having an epoxy group. Of these, an alicyclic epoxy resin is preferable for the reasons described above.

The proportion of the photocurable resin (a1) in the photocurable resin (A) at which the temperature (Tg-Tanδ) at which the loss tangent after curing shows the maximum value is 100 ° C. or higher is 20% by mass to 80% by mass. It is preferably in the range of 30% by mass to 70% by mass, more preferably in the range of 35% by mass to 65% by mass, and more preferably in the range of 40% by mass to 65% by mass. .. When the photocurable resin (A) is an epoxy resin, the ratio of the room temperature solid epoxy resin to the total amount of the epoxy resin is preferably in the range of 20% by mass to 80% by mass, preferably 30% by mass to 70%. The range of mass% is particularly preferable, the range of 35% by mass to 65% by mass is more preferable, and the range of 40% by mass to 65% by mass is more preferable. This is because the heat resistance of the cured sheet can be imparted, while the curing time can be completed in a relatively short time. The ratio of the room temperature solid epoxy resin to the total amount of the epoxy resin can be calculated by the following formula.
<Formula>
Percentage of room temperature solid epoxy resin to total amount of epoxy resin = {Content of room temperature solid epoxy resin [mass part] / (total content of epoxy resin [mass part])} x 100 [mass%]

The photocurable resin (A) preferably has a weight average molecular weight in the range of 100 to 5000, particularly preferably in the range of 150 to 3000, and further preferably in the range of 200 to 2500. preferable. By setting the weight average molecular weight of the photocurable resin (A) within the above range, the sheet shape before curing is more stable and the handleability is improved, and the follow-up adhesion to the adherend surface is improved. Can be done. If the weight average molecular weight of the photocurable resin (A) is too small, the cohesive force of the adhesive layer before curing may be insufficient, and the adhesive layer may seep out over time, resulting in a tendency to deteriorate in handleability. .. On the other hand, if the weight average molecular weight of the photocurable resin (A) is too large, the compatibility with the thermoplastic resin (B) may decrease and the reaction may not proceed easily.

The measurement of the weight average molecular weight described in the present specification is a value measured under the following conditions by a gel permeation chromatograph (GPC) in terms of polystyrene.
(conditions)
-Resin sample solution; 0.4 mass% tetrahydrofuran (THF) solution-Measuring device model number: HLC-8220GPC (manufactured by Tosoh Corporation)
-Column: TSKgel (manufactured by Tosoh Corporation)
-Eluent; tetrahydrofuran (THF)

The content of the photocurable resin (A) in the adhesive layer in the present invention is 10% by mass or more, 15% by mass or more, and 20% by mass in the total amount of the adhesive layer, in other words, the total amount of the adhesive composition. As mentioned above, it is preferably 25% by mass or more, and more preferably 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, and 65% by mass or less. Specifically, it is preferably 10% by mass or more and 90% by mass or less or less than, preferably in the range of 15% by mass to 85% by mass, and preferably in the range of 20% by mass to 80% by mass. Is preferably in the range of 25% by mass to 75% by mass, and preferably in the range of 25% by mass to 65% by mass. By setting the content of the photocurable resin (A) in the adhesive layer in the present invention within the above range, the follow-up adhesion to the step of the adherend surface is further enhanced, and the adhesive layer after curing is used. This is because the two members can be firmly joined. If the content of the photocurable resin (A) is more than the above range, it may not be possible to process it into a sheet, while if it is less than the above range, the adhesive layer after curing Heat resistance may deteriorate.

<Thermoplastic resin (B)>
The thermoplastic resin (B) has a polymerizable functional group other than the polymerizable unsaturated double bond. By containing the thermoplastic resin (B), the adhesive layer in the present invention can react with the photocurable resin (A), suppresses a rapid curing reaction after light irradiation, and cures the reaction. Can be gradually advanced. As a result, the adhesive layer in the present invention can have flexibility even after light irradiation, can follow and adhere to the adherend surface of the member after light irradiation, and has appropriate flexibility even after curing. Therefore, it is possible to firmly join the two members via the adhesive layer.

The polymerizable functional group other than the polymerizable unsaturated double bond of the thermoplastic resin (B) is preferably a group selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group and an epoxy group. By using a thermoplastic resin (B) having at least one polymerizable functional group selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group and an epoxy group, it reacts with the photocurable resin (A). It is possible to suppress the rapid curing reaction after light irradiation, and the curing reaction can be gradually advanced. As a result, the adhesive layer in the present invention can have flexibility even after light irradiation, the follow-up adhesion to the step of the adherend surface is further enhanced, and the two members are firmly joined via the adhesive layer. Because it can be done.

Examples of the thermoplastic resin (B) include polyester resin, polyurethane resin, acrylic resin, polyvinyl acetal resin, epoxy resin (thermoplastic epoxy resin) having a polymerizable functional group other than the polymerizable unsaturated double bond. Can be mentioned. These thermoplastic resins may be homopolymers or copolymers. Further, these thermoplastic resins may be used alone or in combination of two or more.

The polyurethane resin having a polymerizable functional group other than the polymerizable unsaturated double bond is a polyurethane resin (B') having at least one selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group and an epoxy group. Is preferable.

The polyurethane resin (B') can be obtained, for example, by reacting a polyol (b'1) with a polyisocyanate (b'2).

The polyol (b'1) preferably has a number average molecular weight in the range of 500 to 5000, and having a number average molecular weight in the range of 1000 to 3000 is suitable for shape retention, coating workability, initial cohesive force, and the like. It is more preferable to obtain an excellent adhesive layer. The number average molecular weight is a value measured under the following conditions.

The measurement of the number average molecular weight described in the present specification is a value measured under the following conditions by a gel permeation chromatograph (GPC) in terms of polystyrene.
(conditions)
-Resin sample solution; 0.4 mass% tetrahydrofuran (THF) solution-Measuring device model number: HLC-8220GPC (manufactured by Tosoh Corporation)
-Column: TSKgel (manufactured by Tosoh Corporation)
-Eluent; tetrahydrofuran (THF)

As such a polyol (b'1), for example, one or more selected from the group consisting of polyester polyols, polycarbonate polyols and polyether polyols can be preferably used.

Above all, in the present invention, as the polyol (b'1), it is preferable to use at least one or two or more of polyester polyol and polycarbonate polyol, and at least one or two or more polyester polyols are used. Is preferable. In a more preferable example, it is preferable to use two or more kinds of polyester polyols as the polyol (b'1). In another preferable example, it is preferable to use one or more polyester polyols and one or more polycarbonate polyols as the polyol (b'1). In another preferred example, it is preferable to use one or more polyester polyols and one or more polyether polyols as the polyol (b'1). By using different types of polyester polyols in combination, or by using polyester polyols and other polyols in combination, the adhesive sheet of the present invention has a more stable sheet shape before curing and improved handleability, and is adhered. This is because the follow-up adhesion to the step on the surface is improved.

The ratio of the total amount of the polyol selected from the polyester polyol, the polycarbonate polyol, and the polyether polyol to the above polyol (b'1) shall be 20% by mass or more in total in the total amount of the above polyol (b'1). Is more preferable, and 50% by mass or more is more preferable, and 100% by mass is particularly preferable. This is because the adhesive layer containing the polyurethane resin (B') can maintain a level of adhesiveness that can be attached at room temperature, and can further improve the follow-up adhesion to the adherend surface.

When the above-mentioned polycarbonate polyol and the above-mentioned polyester polyol are used in combination, the mass ratio of the polycarbonate polyol and the polyester polyol (polycarbonate polyol / polyester polyol) is preferably in the range of 0.4 to 7.0. It is preferably in the range of 0 to 2.0. A polyurethane resin having a loss tangent (tan δ40 and tanδ60) value within a desired range can be obtained, and an adhesive layer having excellent handleability before curing and having higher follow-up adhesion to an adherend surface can be formed. Because it can be done. Further, the mass ratio of the polyether polyol and the polyester polyol (polyester polyol / polyester polyol) when the above-mentioned polyether polyol and the above-mentioned polyester polyol are used in combination can be the same as the above-mentioned range.

Examples of the polyester polyol include those obtained by esterifying a low molecular weight polyol and a polycarboxylic acid, polyesters obtained by ring-opening polymerization reaction of a cyclic ester compound such as ε-caprolactone, and copolyesters thereof. Etc. can be used.

Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and neopentyl, which have a molecular weight of about 50 to 300. An aliphatic alkylene glycol such as glycol or 1,3-butanediol, cyclohexanedimethanol or the like can be used.

Examples of the polycarboxylic acid that can be used for producing the polyester polyol include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and naphthalenedicarboxylic acid. Aromatic dicarboxylic acids such as acids and their anhydrides or esterified products can be used.

As the polyester polyol, it is preferable to use an aliphatic polyester polyol, and it is more preferable to use a linear aliphatic polyester polyol. A polyurethane resin (B') having a loss tangent (tan δ40 and tanδ60) value within a desired range can be obtained, and an adhesive layer having excellent handleability before curing and higher follow-up adhesion to an adherend surface can be obtained. Because it can be formed. The linear aliphatic polyester polyol refers to a polyester polyol having no alkyl group in the side chain.

Examples of the aliphatic polyester polyol include those obtained by reacting the aliphatic alkylene glycol with an aliphatic dicarboxylic acid, and the aliphatic polyester polyol obtained by esterifying 1,6-hexanediol and adipic acid. It is preferable to use a polyester polyol.

Further, it is preferable to use an aromatic polyester polyol as the polyester polyol. This is because the elastic modulus of the polyurethane resin (B') can be increased to improve the rigidity, and it is possible to suppress the bonding deviation, warpage, and deformation with time before and after the curing of the adhesive layer. Examples of the aromatic polyester polyol include those obtained by reacting an aromatic polyol with an aliphatic or aromatic dicarboxylic acid. For example, an ethylene oxide adduct of bisphenol A is reacted with phthalic acid and adipic acid. The obtained aromatic polyester polyol is preferably used.

As the polyester polyol, only the aliphatic polyester polyol may be used, only the aromatic polyester polyol may be used, or the aliphatic polyester polyol and the aromatic polyester polyol may be used in combination. Among them, the polyester polyol is a combination of an aliphatic polyester polyol and an aromatic polyester polyol, that is, the polyester polyol is one or more aromatic polyester polyols and one or two aliphatic polyester polyols. It is preferable to use more than a seed. The adhesive layer containing the polyurethane resin (B') prepared by the combined use of the aromatic polyester polyol and the aliphatic polyester polyol can balance the hardness and softness of the layer before and after curing, and can be used on the adherend surface. This is because it exhibits high follow-up adhesion to the step and can suppress the bonding deviation, warpage, and deformation of the adhesive layer over time.
In order to balance the above-mentioned contradictory physical properties, the content ratio of the aromatic polyester polyol and the aliphatic polyester polyol (aromatic polyester polyol / aliphatic polyester polyol) is in the range of 20/80 to 90/10 in terms of mass ratio. It is preferably in the range of 50/50 to 80/20, and more preferably in the range of 50/50 to 80/20.

The polyester polyol preferably has a number average molecular weight in the range of 1000 to 5000. A polyurethane resin (B') having a loss tangent (tan δ40 and tanδ60) value within a desired range can be obtained, and the adhesive layer has excellent handleability before curing and has higher follow-up adhesion to the adherend surface. Because it can be done.

In particular, when a polyester polyol obtained by reacting an aliphatic diol such as 1,2-ethanediol or 1,4-butanediol with adipic acid is used as the polyester polyol, the range is in the range of 1100 to 2900. It is preferable to use one having a number average molecular weight of 1,6-hexanediol, and when a polyester polyol obtained by reacting 1,6-hexanediol with adipic acid is used, it has a number average molecular weight in the range of 1100 to 5000. When using a polyester polyol obtained by reacting 1,6-hexanediol with sebacic acid, it is possible to use a polyester polyol having a number average molecular weight in the range of 1000 to 5000. preferable.

When the polyol (b'1) contains a polyester polyol and a polyol other than the polyester polyol, the polyester polyol is used in the range of 10% by mass to 80% by mass with respect to the total amount of the polyol (b'1). It can be used in the range of 20% by mass to 80% by mass, more preferably in the range of 30% by mass to 70% by mass, and more preferably in the range of 40% by mass to 50% by mass. Is more preferable. This is because the adhesive layer containing the polyurethane resin (B') can maintain a level of adhesiveness that can be applied at room temperature, and can further improve the follow-up adhesion to the step of the adherend surface. be.

As the polycarbonate polyol, for example, one obtained by reacting a carbonic acid ester and / or phosgene with a small molecule polyol can be used. As the carbonic acid ester, for example, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

Examples of the low molecular weight polyol capable of reacting with the above-mentioned carbonate ester and phosgen include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol and tripropylene glycol. , 1,2-Butanediol, 1,3-Butanediol, 1,4-Butanediol, 2,3-Butanediol, 1,5-Pentylene diol, 1,5-hexanediol, 1,6-Hexanediol, 2,5-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2 -Methyl-1,3-propanediol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol , 2-Methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4'-biphenol and the like can be used.

Further, it is preferable to use an aliphatic polycarbonate polyol or an alicyclic polycarbonate polyol as the polycarbonate polyol.

The aliphatic polycarbonate polyol is one selected from the group consisting of dialkyl carbonate, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol and 1,6-hexanediol. It is preferable to use the one obtained by reacting with the above polyol. This is because the adhesive layer containing the polyurethane resin (B') can have a level of adhesiveness that can be attached at room temperature.

As the alicyclic polycarbonate polyol, for example, it is preferable to use one obtained by reacting a dialkyl carbonate with a polyol containing at least one selected from the group consisting of cyclohexanedimethanol and its derivatives. This is because the adhesive layer containing the polyurethane resin (B') can have a level of adhesiveness and excellent initial cohesive force that can be attached at room temperature.

The polycarbonate polyol preferably has a number average molecular weight in the range of 500 to 5000, and preferably has a number average molecular weight in the range of 800 to 3000. A polyurethane resin (B') having a loss tangent (tan δ40 and tanδ60) value within a desired range can be obtained, and the adhesive layer has excellent handleability before curing and has higher follow-up adhesion to the adherend surface. Because it can be done.

When the polyol (b'1) contains the polycarbonate polyol and a polyol other than the polycarbonate polyol, the polycarbonate polyol is in the range of 20% by mass to 80% by mass with respect to the total amount of the polyol (b'1). It is preferably used, more preferably in the range of 30% by mass to 70% by mass, and preferably in the range of 40% by mass to 50% by mass. This is because the adhesive layer containing the polyurethane resin (B') can maintain a level of adhesiveness that can be applied at room temperature under light, and can further improve the follow-up adhesion to the adherend surface. ..

Examples of the above-mentioned polyether polyol include those obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator.

Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylolethylene, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, bisphenol A, glycerin, and tri. Methylolethane, trimethylolpropane, etc. can be used.

As the alkylene oxide, for example, ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran and the like can be used.

As the above-mentioned polyether polyol, it is preferable to use an aliphatic polyether polyol or a polyether polyol having an alicyclic structure.

Examples of the above-mentioned polyether polyol include polytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, a polytetramethylene glycol derivative obtained by reacting tetrahydrofuran with alkyl-substituted tetrahydrofuran, and neopentyl glycol and tetrahydrofuran are copolymerized. Polytetrahydrofuran glycol derivatives and the like can be used. Among them, as the above-mentioned polyether polyol, the adhesive sheet containing the above-mentioned adhesive layer maintains a level of stickability that is possible at room temperature, and has excellent flexibility, durability (particularly hydrolysis resistance) and the like. For improvement, it is preferable to use polytetramethylene glycol (PTMG) and polytetramethylene glycol derivative (PTXG).

Further, as the above-mentioned polyol (b'1), other polyols can be used in addition to the above-mentioned polyols. Examples of the other polyols include acrylic polyols.

As the polyisocyanate (b'2), an alicyclic polyisocyanate, an aliphatic polyisocyanate, an aromatic polyisocyanate or the like can be used, and it is preferable to use an alicyclic polyisocyanate.

Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 4,4′-dicyclohexylmethanediisocyanate, 2,4- and / or 2,6-methylcyclohexanediisocyanate, and cyclohexyl. Sirenized isocyanate, methylcyclohexylene diisocyanate, bis (2-isosyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate and 2,5- and / or 2,6-norbornane diisocyanate, diisocyanate dimerate, bicycloheptane Triisocyanate and the like can be used alone or in combination of two or more.

Among the above-mentioned alicyclic polyisocyanates, 4,4'in order to obtain an adhesive sheet having good reactivity with the above-mentioned polyol (b'1) and excellent in heat resistance and light transmittance. -Dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,3-bis (isocyanatomethyl) cyclohexane (BICH) are preferably used.

As a method for producing a polyurethane resin (B') having an isocyanate group by reacting the polyol (b'1) with the polyisocyanate (b'2), for example, the polyol (b'1) charged in a reaction vessel. After removing water by heating under normal pressure or reduced pressure conditions, the above polyisocyanate (b'2) may be supplied in a lump or divided manner for reaction.

The reaction between the polyol (b'1) and the polyisocyanate (b'2) is an equivalent ratio of the isocyanate group of the polyisocyanate (b'2) to the hydroxyl group of the polyol (b'1) ( Hereinafter, it is referred to as [NCO / OH equivalent ratio]), preferably in the range of 1.1 to 20.0, more preferably in the range of 1.1 to 13.0, and 1.1 to 5. It is more preferably carried out in the range of 0, and particularly preferably carried out in the range of 1.5 to 3.0.

The reaction conditions (temperature, time, etc.) between the polyol (b'1) and the polyisocyanate (b'2) may be appropriately set in consideration of various conditions such as safety, quality, and cost, and are not particularly limited. For example, the reaction temperature is preferably in the range of 70 to 120 ° C., and the reaction time is preferably in the range of 30 minutes to 5 hours.

When the polyol (b'1) is reacted with the polyisocyanate (b'2), for example, a tertiary amine catalyst, an organic metal catalyst, or the like can be used as a catalyst, if necessary. ..

Further, the above reaction may be carried out in a solvent-free environment or in the presence of an organic solvent. Examples of the organic solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate, ketone solvents such as acetone, methyl ethyl ketone, methyl butyl ketone and cyclohexanone, and ether esters such as methyl cellosolve acetate and butyl cellosolve acetate. A system solvent, an aromatic hydrocarbon solvent such as toluene and xylene, and an amide solvent such as dimethylformamide and dimethylacetamide can be used alone or in combination of two or more. The organic solvent may be removed during the production of the polyurethane resin (B') or after the production of the polyurethane resin (B') by an appropriate method such as heating under reduced pressure or drying at normal pressure.

As the polyurethane resin (B') having an isocyanate group, for example, a polyurethane resin (B'1) having an isocyanate group obtained by reacting a polyol (b'1) with a polyisocyanate (b'2) is used. can do. For details (type, composition, etc.) of the polyol (b'1) and polyisocyanate (b'2) used for preparing the polyurethane resin (B') having an isocyanate group, refer to the above-mentioned polyol (b'1) and poly. It can be the same as the details of isocyanate (b'2).

As the polyurethane resin (B') having a hydroxyl group, for example, a polyurethane resin (B'2) having a hydroxyl group obtained by reacting a polyol (b'1) with a polyisocyanate (b'2) is used. Can be done.

For details (type, composition, etc.) of the polyol (b'1) and polyisocyanate (b'2) used for preparing the polyurethane resin (B') having a hydroxyl group, refer to the polyurethane resin (B') having an isocyanate group. The details of the polyol (b'1) and polyisocyanate (b'2) used in the synthesis can be the same.

Examples of the polyurethane resin (B') having an oxetanyl group or an epoxy group include 1) polyurethane having an isocyanate group (B'1).
2) A monomer having a functional group (b "1) capable of reacting with an isocyanate group, an oxetanyl group or an epoxy group, and a polymerizable functional group (b" 2) other than one or more polymerizable unsaturated double bonds. (B ") and
Polyurethane resin (B'3) obtained by reacting with can be used.

As the functional group (b "1) capable of reacting with the isocyanate group, for example, a hydroxyl group, an amino group, a carboxyl group, a mercapto group and the like can be used, and among them, a hydroxyl group and an amino group are preferably used.

The polymerizable functional group (b "2) other than the above-mentioned polymerizable unsaturated double bond refers to a functional group other than the so-called radically polymerizable functional group, for example, a cationically polymerizable functional group and an anionic polymerizable functional group. It is a functional group or the like, and examples thereof include an epoxy group, an oxetanyl group and an ethylene sulfide group.

The monomer (B ") is not particularly limited as long as it has a functional group (b" 1) and a polymerizable functional group (b "2), and is not particularly limited, for example, 3-ethyl-. Examples thereof include 3- (4-hydroxybutyl) oxymethyl-oxetane, 3-hydroxymethyl-3-ethyloxetane, 2-hydroxymethyloxetane, and 3-hydroxyoxetane.

The monomer (B ") is preferably used in the range of 5 parts by mass to 20 parts by mass with respect to 100 parts by mass of the polyurethane resin (B'1), and is preferably used in the range of 5 parts by mass to 15 parts by mass. It is more preferable to use it.

More specifically, the monomer (B ") is more preferably more than 50 mol% and 100 mol% or less, more preferably 100 mol% or less, based on the number of moles of the isocyanate group contained in the polyurethane resin (B'1). An amount capable of supplying a functional group capable of reacting with the above-mentioned isocyanate group, which is 60 mol% to 100 mol%, more preferably 80 mol% to 100 mol%, can be used. It is possible to obtain a polyurethane resin having excellent quick-curing property, shape retention, mechanical strength, durability (particularly hydrolysis resistance), and follow-up adhesion to an adherend surface.

When the urethane resin (B'1) and the monomer (B ") are reacted, a urethanization catalyst can be used if necessary. The urethanization catalyst is the urethanization reaction. The urethanization reaction is preferably carried out until the isocyanate group content (%) becomes substantially constant. Examples of the urethanization catalyst include triethylamine and tri. Nitrogen-containing compounds such as ethylenediamine and N-methylmorpholin, organic metal salts such as potassium acetate, zinc stearate and stannous octylate, and organic metal compounds such as dibutyltin dilaurate can be used.

Further, the epoxy resin having a polymerizable functional group other than the polymerizable unsaturated double bond is a polymer or copolymer of epoxy compounds having a linear structure, or an epoxy compound and this epoxy compound. Examples thereof include a copolymer with a polymerizable monomer and having a linear structure. Specifically, bisphenol A type epoxy resin, bisphenol fluorene type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, cyclic aliphatic type epoxy resin, long chain aliphatic type epoxy resin, glycidyl ester type epoxy resin, Examples thereof include glycidylamine type epoxy resin, and bisphenol A type epoxy resin and bisphenol fluorene type epoxy resin are preferable.

Among them, the adhesive layer in the present invention is a resin selected from the group consisting of a polyurethane resin, an acrylic resin and an epoxy resin having a polymerizable functional group other than a polymerizable unsaturated double bond as the thermoplastic resin (B). Is preferably contained in an amount of one or more, and at least one or two or more polyurethane resins having a polymerizable functional group other than the polymerizable unsaturated double bond are preferably contained. By using a polyurethane resin having a polymerizable functional group other than the polymerizable unsaturated double bond as the thermoplastic resin (B), a rapid curing reaction can be suppressed after light irradiation and the curing reaction can be gradually advanced. Since it is possible, it is possible to have the flexibility required for bonding even after light irradiation. As a result, the adhesive layer in the present invention can follow and adhere to the adherend surface of the member after light irradiation, and has appropriate flexibility even after curing. Therefore, the members can be brought together via the adhesive layer. It is possible to firmly join.

The melting point of the thermoplastic resin (B) is preferably in the range of 30 ° C. to 120 ° C., particularly preferably in the range of 35 ° C. to 100 ° C., and further preferably in the range of 40 ° C. to 80 ° C. By using the thermoplastic resin (B) having a melting point within the above range, the adhesive sheet of the present invention has a more stable sheet shape before curing and improved handleability, and also adheres to the adherend surface. The sex can be improved.

The melting point of the thermoplastic resin (B) is raised from 20 ° C. to 150 ° C. under a heating rate of 10 ° C./min using a differential scanning calorimetry method (DSC method), and then held for 1 minute. The maximum exothermic peak (exothermic peak top) observed when the temperature is once cooled to -10 ° C under the temperature lowering condition of 10 ° C./min, held for 10 minutes, and then measured again under the temperature rise condition of 10 ° C./min is shown. Refers to temperature.

The thermoplastic resin (B) preferably has a weight average molecular weight in the range of 5500 to 2000000, more preferably in the range of 5500 to 1000000, and even more preferably in the range of 5500 to 800,000. .. By setting the weight average molecular weight of the thermoplastic resin (B) within the above range, the sheet shape before curing can be made more stable and handleability can be improved, and the follow-up adhesion to the adherend surface can be improved. can. If the weight average molecular weight of the thermoplastic resin (B) is too small, the cohesive force of the adhesive layer before curing may be insufficient, and the adhesive layer may exude over time, and the handleability may be easily deteriorated. On the other hand, if the weight average molecular weight of the thermoplastic resin (B) is too large, the compatibility with the photocurable resin (A) may decrease and the reaction may not proceed easily.

The content of the thermoplastic resin (B) in the adhesive layer in the present invention is 5% by mass or more, 10% by mass or more, and 20% by mass or more in the total amount of the adhesive layer, in other words, the total amount of the adhesive composition. , 30% by mass or more, and more preferably 80% by mass or less, 70% by mass or less, 60% by mass or less, and 50% by mass or less. Specifically, it is preferably in the range of 5% by mass to 80% by mass, preferably in the range of 10% by mass to 60% by mass, and preferably in the range of 20% by mass to 50% by mass. preferable. By setting the content of the thermoplastic resin (B) in the adhesive layer in the present invention within the above range, it is possible to have the flexibility to ensure the followability to the adherend even after light irradiation. This is because it is possible to suppress the elongation of the adhesive layer in the dicing step while maintaining appropriate flexibility even after curing. If the content of the thermoplastic resin (B) is more than the above range, the heat resistance of the cured product may deteriorate, while if it is less than the above range, it occupies a high proportion of the entire adhesive layer. In some cases, the proportion of molecular weight components decreases and it cannot be processed into a sheet.

The content ratio of the thermoplastic resin (B) to the content of the photocurable resin (A) ([content of thermoplastic resin (B) / content of photocurable resin (A)]) is based on mass. It is preferably in the range of 0.1 to 10, preferably in the range of 0.15 to 2, preferably in the range of 0.2 to 1.7, and preferably in the range of 0.3 to 1. It is preferably in the range of .5, preferably in the range of 0.5 to 1.4, and preferably in the range of 0.5 to 1.0. By setting the content ratio of the thermoplastic resin (B) to the content of the photocurable resin (A) within the above range, the flexibility of ensuring the followability to the adherend even after light irradiation can be ensured. It can be applied and the adhesive layer can be made difficult to stretch in the dicing step after curing. Further, by lowering the ratio of the thermoplastic resin (B) than that of the photocurable resin (A), excellent adhesive reliability after curing can be obtained, and further excellent adhesiveness at high temperature can be obtained. be able to.

<Photopolymerization initiator (C)>
When the adhesive layer in the present invention contains one or more photopolymerization initiators (C), the reactivity after irradiation with active energy rays is promoted, and the bondability after curing can be enhanced. Further, since the adhesive layer contains the photopolymerization initiator (C) which is activated by light and the reaction proceeds, the reaction continues as it is even after the irradiation with the active energy rays is stopped, so that it is dark. The reaction proceeds even in a place or at a low temperature, and a good curing reaction can be obtained. As a result, high bondability can be obtained without damaging the members to be joined, deforming the members due to strain between the members, or causing cracks between the adhesive sheet and the members.

The photopolymerization initiator (C) is not particularly limited as long as it is activated by light. Examples of the photopolymerization initiator (C) include a photoradical polymerization initiator, a photocationic polymerization initiator, and a photoanionic polymerization initiator. Among them, at least one of the photocationic polymerization initiator and the photoanionic polymerization initiator. Is preferable, and a photocationic polymerization initiator is more preferable because the polymerization by a dark reaction can be preferably adjusted.

The photocationic polymerization initiator is not particularly limited as long as it can induce a ring-opening reaction of a cationically polymerizable functional group by light of a wavelength used. Among them, a compound that induces a ring-opening reaction of a cationically polymerizable functional group by wavelength light of 300 nm to 370 nm and is inactive in a wavelength region exceeding 370 nm is preferably used. Examples of such a photocationic polymerization initiator include onium salts such as aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts.

Specific examples of onium salts include, for example, Optomer SP-150, Optomer SP-170, Optomer SP-171 (all manufactured by ADEKA), UVE-1014 (manufactured by General Electronics), OMNICAT250, OMNICAT270 (all manufactured by IGM Resin). IRGACURE290 (BASF), Sun Aid SI-60L, Sun Aid SI-80L, Sun Aid SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.), CPI-100P, CPI-101A, CPI-200K (all manufactured by Sanshin Chemical Industry Co., Ltd.) (Manufactured by Sun Appro) and the like.

The photocationic polymerization initiator may be used alone or in combination of two or more. Further, a plurality of photocationic polymerization initiators having different effective active wavelengths may be used for two-step curing.

The photocationic polymerization initiator may be used in combination with an anthracene-based or thioxanthone-based sensitizer, if necessary.

The photocationic polymerization initiator is preferably contained in the range of 0.001% by mass to 30% by mass with respect to the total amount of the adhesive layer, in other words, the adhesive composition forming the adhesive layer. It is preferably contained in the range of 01% by mass to 20% by mass, and more preferably contained in the range of 0.1% by mass to 10% by mass. If the blending ratio of the photocationic polymerization initiator is too small, the curing required for the development of high bondability will be insufficient, and if it is too large, the curing property will be improved, but the curing reaction will proceed faster after light irradiation. It is difficult to firmly follow and adhere to the adherend surface and firmly join the members.

<Filler (D)>
The adhesive layer in the present invention contains the filler (D) within a predetermined content range. In the present invention, the content of the filler (D) in the adhesive layer may be 5% by mass or more and 45% by mass or less, particularly preferably 6% by mass or more and 43% by mass or less, and 7% by mass. It is more preferably 40% by mass or more, more preferably 8% by mass or more and 39% by mass or less, and particularly preferably 10% by mass or more and 35% by mass or less. By setting the content of the filler (D) in the total amount of the adhesive layer (total amount of the adhesive composition) within the above range, the adhesive sheet can adhere to the adherend without being hindered by the filler (D). On the other hand, it is possible to suppress the generation of burrs during dicing. If the content of the filler (D) is too large, the adhesion to the adherend may be poor, and if it is too small, burrs may occur during dicing.

The volume ratio of the filler (D) in the adhesive layer is preferably 2% by volume or more and 30% by volume or less, more preferably 3% by volume or more and 27% by volume or less, and 3.5 volumes. It is more preferably% or more and 25% by volume or less, and particularly preferably 4% by volume or more and 22% by volume or less. By setting the volume ratio of the filler (D) in the adhesive layer within the above range, the adhesive sheet can adhere to the adherend without being hindered by the filler (D), while burrs are generated during dicing. This is because it can suppress. If the volume ratio of the filler (D) in the adhesive layer is too large, the adhesion to the adherend may be poor, and if it is too small, burrs may occur during dicing.

For the volume ratio of the filler (D) in the adhesive layer, the volume of the filler (D) is calculated from the value obtained by dividing the content weight of the filler (D) in the adhesive layer by the specific gravity of the filler (D). , The value was calculated by dividing the value by the volume of the adhesive layer.

The filler (D) may be used alone or in combination of two or more.

The filler (D) may be an inorganic filler or an organic filler. Further, the adhesive layer in the present invention may contain one or more kinds of inorganic fillers or organic fillers, and one kind or two or more kinds of inorganic fillers and one kind or two or more kinds of organic fillers. It may be contained.

Examples of the inorganic filler include fillers composed of inorganic materials such as metals, metal compounds, alloys, inorganic salts, carbon materials, and clay minerals. Specific examples of the inorganic material include metals such as aluminum, gold, silver, copper, and nickel and their alloys; calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium hydrogen carbonate, Potassium hydrogen carbonate, calcium hydrogen carbonate, magnesium hydrogen carbonate, zinc carbonate, calcium phosphate, magnesium phosphate, sodium phosphate, potassium phosphate, barium phosphate, sodium citrate, potassium citrate, calcium citrate, magnesium citrate, magnesium oxalate, Inorganic salts such as sodium oxalate, potassium oxalate, sodium tartrate, potassium tartrate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide; metal sulfides such as zinc sulfide; titanium nitride, aluminum nitride, silicon nitride, nitride Metal nitrides such as boron; Viscosites such as talc and mica; Metal hydroxides such as aluminum hydroxide and magnesium hydroxide; Metal oxides such as aluminum oxide and titanium oxide; Aluminum borate whisker, crystalline silica, non- Crystalline silica, amorphous carbon, graphite, glass and the like can be mentioned.

The inorganic filler preferably exhibits basicity. Since the inorganic filler is basic, the inorganic filler captures the acid generated in the adhesive layer and the metal ions generated on the adhered surface, especially when the adherend surface of the member to be bonded contains a metal surface. This is because the corrosion of the metal surface can be suppressed.

Examples of the inorganic filler exhibiting basicity include inorganic salts and metal compounds having a basic group introduced on the surface. A metal compound having a basic group introduced on its surface can be obtained by subjecting the surface of the metal compound to a basic treatment. The basic treatment refers to a treatment in which the surface of a metal compound is made basic by reacting or adsorbing a nitrogen compound such as a silane coupling agent having a basic group or hexamethyldisilazane on the metal compound. The basic treatment is not limited to the treatment as long as the surface of the metal compound can be made basic. Examples of the basic group include an organic amino group and a hydroxyl group.

Moreover, as an organic filler, a filler composed of a resin material can be mentioned. Specific examples of the resin material include polymethyl methacrylate (PMMA), polyimide, polyamideimide, polyetheretherketone, polyetherimide, polyesterimide and the like.

The filler (D) can have various shapes such as a particle shape, a needle shape, and a flake shape. Of these, particulate matter is preferable from the viewpoint of uniform dispersibility and the like. When the filler (D) is in the form of particles, the average particle size of the filler (D) is preferably 0.5 μm or more and 100 μm or less, more preferably 1 μm or more and 100 μm or less, and 2 μm or more and 90 μm or less. It is more preferable, and it is particularly preferable that it is 3 μm or more and 50 μm or less. This is because by using a filler having an average particle size within the above range, the end face of the adhesive layer does not stretch during dicing and is appropriately cut, so that burrs are less likely to occur. If the average particle size of the filler (D) is larger than the above range, it may be difficult to process it into a sheet, and if it is smaller than the above range, the adhesive layer may be stretched during dicing.

When the filler (D) is a primary particle without agglutination, the average particle size of the primary particle is preferably within the above range. On the other hand, when the filler (D) aggregates to form secondary particles, the size of the secondary particles is preferably in the above range.

The average particle size of the filler (D) is a value measured by scanning electron microscopy (SEM). Specifically, the average particle size was measured using a surface observation device (VE-9800 manufactured by KEYENCE CORPORATION).

Above all, the adhesive layer in the present invention preferably contains an inorganic filler as the filler (D), and contains at least one or more fillers composed of an inorganic material selected from inorganic salts and metal compounds. Is more preferable, and it is more preferable to contain at least one of calcium carbonate particles and silica particles.

The filler (D) is preferably dispersed in the adhesive layer. This is because if the filler (D) is unevenly distributed, the generation of burrs cannot be sufficiently suppressed in the entire area of the adhesive layer during the dicing process. Here, the fact that the filler (D) is dispersed in the adhesive layer means that an arbitrary place after sheet processing is cut into 5 cm × 5 cm, and the filler (D) aggregates over 1000 μm when observed with a microscope. It means that there are less than 3 things.

The filler (D) may be embedded in the adhesive layer, or a part of the surface thereof may be exposed from the adhesive layer.

<Other ingredients (E)>
The adhesive layer contains, if necessary, other components (E) in addition to the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D). can do.

The adhesive layer in the present invention may contain an adhesive resin. This is because the adhesive sheet of the present invention can exhibit good normal temperature adhesion and can further improve the follow-up adhesion to the adherend surface.

The adhesive resin preferably has a weight average molecular weight in the range of 2000 to 2000000, more preferably in the range of 5000 to 10000, and more preferably in the range of 5000 to 800,000.

Examples of the adhesive resin include polyester resin, polyurethane resin, poly (meth) acrylate resin, polyvinyl acetal resin and the like. These adhesive resins may be homopolymers or copolymers. Further, these adhesive resins may be used alone or in combination of two or more.

The adhesive resin preferably has a glass transition temperature in the range of −30 ° C. to 20 ° C., and more preferably in the range of −25 ° C. to 10 ° C. When the adhesive layer contains an adhesive resin having a glass transition temperature within the above range, the adhesive sheet of the present invention can exhibit good adhesiveness and high elastic modulus at room temperature, and can be applied to an adherend. It is possible to show good adhesiveness and high bonding strength.

For the glass transition temperature, for example, using a dynamic viscoelasticity tester (manufactured by Leometrics, trade name: Ares 2KSTD), a test piece of adhesive resin is sandwiched between parallel disks, which is the measurement part of the tester. The storage elastic modulus (G') and the loss elastic modulus (G ") at a frequency of 1 Hz are measured, and the loss elastic modulus (G") is divided by the storage elastic modulus (G') (G "/ G'". ) Can be calculated as the temperature at which the loss tangent (tan δ) that can be calculated is the maximum value.

The adhesive resin may be introduced with a cross-linking agent or a functional group capable of reacting with a functional group contained in the above-mentioned photocurable resin (A) or thermoplastic resin (B). This is because the adhesive resin can be crosslinked. Examples of the functional group include a hydroxyl group, a carboxyl group, an epoxy group, an amino group and the like, and they should be selected in a timely manner as long as they do not inhibit the polymerization reaction of the photocurable resin (A) and the thermoplastic resin (B). Is preferable.

The adhesive resin is preferably contained in the range of 0.1 part by mass to 100 parts by mass in the total amount of the adhesive layer, in other words, in the total amount of the adhesive composition forming the adhesive layer, and 1 mass by mass. It is preferably contained in the range of parts to 50 parts by mass, and preferably contained in the range of 5 parts by mass to 30 parts by mass. By setting the blending ratio of the adhesive resin within the above range, it is possible to obtain an adhesive sheet having excellent adhesiveness at room temperature without deteriorating the adhesiveness of the adhesive layer after curing. be.

The adhesive layer in the present invention may contain a silane coupling agent, a phosphoric acid-based additive, an acrylate-based additive, and the like as other components. When glass is contained in the material of the adherend surface, the adhesive layer can further enhance the adhesiveness to the adherend by containing a silane coupling agent having high reactivity with glass. Further, the adhesive layer may contain a photocurable silane coupling agent capable of reacting with a photocurable resin (A), a thermoplastic resin (B), or the like.

Further, the adhesive layer in the present invention has other components such as a softening agent, a stabilizer, an adhesion accelerator, a leveling agent, a defoaming agent, a plasticizer, a tackifier resin, fibers, an antioxidant, and an antioxidant. It can contain any component such as an agent, a thickener, a colorant such as a pigment, a filler, and a tackifier resin.

<Others>
The adhesive layer in the present invention contains one or more resins (AA) having an epoxy group or an oxetanyl group and having a weight average molecular weight in the range of 100 to 5000, except for a polymerizable unsaturated double bond. It is selected from the group consisting of polyester resin, polyurethane resin, acrylic resin, polyvinyl acetal resin and epoxy resin (thermoplastic epoxy resin) having a polymerizable functional group of The resin (BB) contains one or more types, a photopolymerization initiator (C), and a filler (D), and the content of the filler (D) in the adhesive layer is 5% by mass or more 45. It is preferably mass% or less. The effect of the present invention can be achieved by having the above-mentioned composition containing two or more kinds of resins in which a resin having a low weight average molecular weight and a resin having a high weight average molecular weight are combined. Here, the resin (AA) and the resin (BB) correspond to the above-mentioned photocurable resin (A) and thermoplastic resin (B), respectively.

<Physical characteristics of the adhesive layer>
The thickness of the adhesive layer in the present invention is preferably 10 μm or more and 3000 μm or less, preferably 20 μm or more and 2500 μm or less, 30 μm or more and 2000 μm or less, and 50 μm or more and 650 μm or less. This is because when the thickness of the adhesive layer is within the above range, the handleability before curing is excellent, high follow-up adhesion to the adherend surface and the effect of suppressing metal corrosion can be exhibited. If the thickness of the adhesive layer is smaller than the above range, the desired amount of the filler (D) cannot be contained, and defects such as burrs and floating from the adherend surface during dicing processing cannot be contained. It may not be possible to sufficiently suppress the occurrence of the above-mentioned, or it may not be possible to obtain sufficient adhesive strength due to the thin thickness. On the other hand, if the thickness of the adhesive layer is larger than the above range, it is difficult to process it into a sheet shape. As will be described later, when the adhesive layer in the present invention is a multilayer body in which a plurality of adhesive layers are laminated, the thickness of the adhesive layer means the total thickness of the multilayer body.

The adhesive layer in the present invention preferably has a loss tangent (tan δ) of less than 1.5 at a frequency of 1.0 Hz and a temperature of 23 ° C. before curing, and is preferably 0.01 or more and 1.0 or less. Is more preferable, and more preferably 0.1 or more and 0.8 or less. This is because the thickness of the adhesive sheet can be kept constant, the handleability before curing is excellent, and the follow-up adhesion to the adherend surface is further improved before and after curing.

For loss tangent (tan δ) of the adhesive layer, prepare a test piece obtained by cutting the adhesive layer into a circle with a thickness of 1 mm and a diameter of 8 mm, and prepare a dynamic viscoelasticity tester (manufactured by Leometrics). Using the name: Ares 2KSTD), sandwich the prepared test piece between the parallel disks, which are the measuring parts of the testing machine, and store elastic modulus (G') and loss elasticity at a frequency of 1.0 Hz and a temperature of 23 ° C. The rate (G ″) is measured, and the loss tangent (tan δ) is a value (G ″ / G ′) obtained by dividing the loss elastic modulus (G ″) by the storage elastic modulus (G ′).

The loss tangent (tan δ) of the adhesive layer can be adjusted by appropriately selecting the composition of the photocurable resin (A), the thermoplastic resin (B), other components, and the average molecular weight thereof, if necessary. can.

The adhesive layer in the present invention preferably has a melting point of 25 ° C. or higher, preferably 30 ° C. or higher, preferably 35 ° C. or higher, and preferably 40 ° C. or higher. The melting point is preferably 120 ° C. or lower, preferably 90 ° C. or lower, and preferably 60 ° C. or lower. More specifically, the melting point of the adhesive layer is preferably in the range of 30 ° C. to 120 ° C., preferably in the range of 30 ° C. to 90 ° C., and preferably in the range of 40 ° C. to 85 ° C. By setting the melting point of the adhesive layer within the above range, the adhesive sheet of the present invention is excellent in handleability before curing, and the follow-up adhesion to the adherend surface is further improved. The melting point of the adhesive layer is synonymous with the melting point of the adhesive composition constituting the adhesive layer.

The melting point of the adhesive layer is raised from 20 ° C. to 150 ° C. under a heating rate of 10 ° C./min using the differential scanning calorimetry method (DSC method), held for 1 minute, and then 10 ° C. The temperature that indicates the maximum exothermic peak (exothermic peak top) observed when the temperature is once cooled to -10 ° C under the temperature decrease condition of / min, held for 10 minutes, and then measured again under the temperature rise condition of 10 ° C / min. ..

The adhesive layer in the present invention, the adhesive layer after curing, frequency 1 Hz, preferably the storage modulus at a temperature ₂₅ ℃ (E '25) is 1.0 × ¹⁰ 5 Pa or more, 1.0 It is more preferably × 10 ⁶ Pa or more, and more preferably 1.0 × 10 ⁷ Pa or more. This is because the adhesive layer after curing exhibits a desired storage elastic modulus under predetermined conditions, so that the adhesive layer after bonding can be suppressed from being displaced or deformed over time.

Further, the adhesive layer in the present invention preferably has a storage elastic modulus (E'40) of the cured adhesive layer at a frequency of 1 Hz and a temperature of 40 ° C. of 1.0 × 10 ⁴ Pa or more. 1 Hz, it is preferable that the storage elastic modulus at a temperature 60 ℃ (E'60) is 1.0 × ¹⁰ 4 Pa or more. This is because the cured adhesive layer exhibits a desired storage elastic modulus under predetermined conditions, so that the members can be firmly joined to each other.

The storage elastic modulus of the cured adhesive layer at each temperature is a test formed by punching a cured adhesive layer having a thickness of 100 μm into the shape of a test piece type 5 of JIS K 7127 using a dumbbell cutter. It is a value measured by a dynamic viscoelasticity measuring device (manufactured by Leometrics Co., Ltd., trade name: RSA-II) using a piece.

The adhesive sheet of the present invention preferably has a tensile elongation at break of 0.5% or more when the cured adhesive sheet is pulled at a tensile speed of 300 mm / min at 25 ° C., and more preferably 1.0%. These are 1.5% or more, 2.0% or more, and 3.0% or more. The tensile elongation at break is preferably 30% or less, and more preferably 25% or less, 20% or less, 15% or less, 10% or less. Specifically, the stretch elongation at break can be 1.0% or more and 25% or less, 1.5% or more and 20% or less, 2.0% or more and 15% or less, and 3.0% or more and 10% or less. .. This is because the tensile elongation at break of the adhesive sheet after curing is within the above range, so that the sheet does not stretch excessively during dicing and burrs are unlikely to occur.

The tensile elongation at break of the adhesive sheet after curing can be measured by a method according to JISK7127-1999 [Plastic-Test method for tensile properties-Part 3: Test conditions for film and sheet]. The test piece used for the measurement is an adhesive sheet cut into a size of 10 mm in width × 150 mm in length to have a length of 50 mm between the marked lines (according to test piece type 2 of JISK7127-1999), and air-cooled mercury. ^{After irradiating ultraviolet rays with an intensity of 300 mW / cm 2} for 15 seconds using a lamp (manufactured by Eye Graphics), leave it heated at 80 ° C for 3 hours, leave it in an environment of 23 ° C for 30 minutes or more, and cool it to cool the adhesive layer. Was used.

In the adhesive sheet of the present invention, the gel content of the adhesive layer after curing is preferably 40% by mass or more and 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less, and 70% by mass or more. It is particularly preferably 100% by mass or less. By setting the gel fraction within the above range, the members can be firmly bonded to each other even after curing, and heat resistance can be imparted.

The gel fraction is the dry mass of the adhesive layer remaining in the solvent after immersing the adhesive layer of the cured adhesive sheet of the present invention in toluene adjusted to 23 ° C. for 24 hours. The value is calculated based on the following formula from the mass of the adhesive layer before immersion in toluene.
Gel fraction (% by mass) = {(mass of adhesive layer of adhesive sheet remaining without being dissolved in toluene) / (mass of adhesive layer of adhesive sheet before immersion in toluene)} x 100

(2) Aspects of Adhesive Sheet The adhesive sheet of the present invention may have any configuration as long as it has an adhesive layer containing the above-mentioned composition, if necessary.

As one aspect (aspect (I)) of the adhesive sheet of the present invention, an aspect composed of only an adhesive layer, that is, a substrate-less aspect can be mentioned. The adhesive sheet of aspect (I) is simply composed of an adhesive composition containing at least the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D). The embodiment may have only the adhesive layer of the layer. Further, the adhesive sheet of the aspect (I) has only a multilayer adhesive layer in which two or more layers are laminated, and at least the outermost layers on both sides of the multilayer adhesive layer are the above-mentioned photocurable resin. It may be composed of an adhesive composition containing (A), a thermoplastic resin (B), a photopolymerization initiator (C) and a filler (D), and among them, a plurality of layers constituting a multilayer adhesive layer. Is preferably composed of an adhesive composition containing the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D).

In the adhesive sheet of aspect (I), a release liner may be arranged on one main surface or both main surfaces of the pair of main surfaces facing each other of the adhesive layer. The adhesive sheet of aspect (I) is used by peeling off the release liner when the adhesive sheet is attached to the member. Therefore, in the laminated body in which the pair of members are joined via the adhesive sheet of the aspect (I), the release liner is not included in the structure of the adhesive sheet.

Further, as another aspect of the adhesive sheet of the present invention (aspect (II)), the base material, the first adhesive layer formed on the first main surface of the base material, and the above-mentioned base material. The photocurable resin has a second adhesive layer formed on a second main surface facing the first main surface, and the first adhesive layer and the second adhesive layer are each described above. Examples thereof include an embodiment composed of an adhesive composition containing at least (A), a thermoplastic resin (B), a photopolymerization initiator (C) and a filler (D). The adhesive sheet of aspect (II) has a base material between the two adhesive layers, so that the strength of the sheet can be increased. In the aspect (II), only one of the first adhesive layer and the second adhesive layer is the above-mentioned photocurable resin (A), thermoplastic resin (B), and photopolymerization initiator (). It may be composed of an adhesive composition containing at least C) and a filler (D).

In the adhesive sheet of aspect (II), the base material is not particularly limited, and for example, a plastic film made of polyester resin, polyolefin resin, etc., a plastic foam made of polyolefin resin, polyurethane resin, polychloroprene resin, acrylic resin, etc. Can be used. The base material preferably has light transmission. By irradiating light from one adhesive layer side, the other adhesive layer can also be activated via the base material to cause a polymerization reaction.

The adhesive sheet of aspect (II) is at least one of a surface of the first adhesive layer opposite to the surface in contact with the base material and a surface of the second adhesive layer opposite to the surface in contact with the base material. A release liner may be arranged on the surface, or a release liner may be arranged on both surfaces. The adhesive sheet of aspect (II) is used by peeling off the release liner when the adhesive sheet is attached to the member. Therefore, in the laminated body in which the pair of members are joined via the adhesive sheet of the aspect (II), the release liner is not included in the structure of the adhesive sheet.

Examples of the release liner include paper such as kraft paper, glassin paper, and high-quality paper; resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate; laminated paper obtained by laminating the above paper and the resin film, and clay on the above paper. It is possible to use a product which has been sealed with polyvinyl alcohol or the like and which has been subjected to a peeling treatment such as a silicone resin on one side or both sides.

The thickness of the adhesive sheet of the present invention is preferably 10 μm to 3000 μm, preferably 20 μm or more and 2500 μm or less, preferably 30 μm or more and 2000 μm or less, and preferably 50 μm or more and 650 μm or less.

When the adhesive sheet of the present invention is irradiated with light, polymerization starts in the adhesive layer and curing proceeds. Since the adhesive layer in the present invention is activated by light, curing does not proceed regardless of the storage temperature in a state where it is not irradiated with light, and the storage stability before curing is good. Further, in the adhesive layer of the present invention, since the reactive portion is activated by light irradiation without heating, the curing reaction can proceed even at a low temperature.

The adhesive sheet of the present invention can accelerate the curing reaction by further applying external stimuli such as heat and moisture (humidity) in addition to light. Above all, it is preferable to use light and heat together as a means for curing the adhesive sheet of the present invention. By irradiating the adhesive sheet with light first, the adhesive layer is activated to initiate polymerization, and the adhesive sheet is attached to a member (adhesive body) and then heated to carry out a curing reaction. Can be promoted. As a result, unlike a thermosetting adhesive sheet, curing by high temperature heating becomes unnecessary, and the curing reaction can proceed even at a low temperature. When heat is used in combination, the reaction starts by irradiating light first, so heat is used only for the purpose of accelerating the curing reaction, and it is not necessary to heat at high temperature, and the reaction is carried out at low temperature and in a short time. However, a good curing reaction can be obtained.

(3) Method for Producing Adhesive Sheet The adhesive sheet of the present invention has an adhesive composition containing at least the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D). It can be produced by using an adhesive solution in which the product is mixed with a solvent. Specifically, the adhesive sheet of the present invention is produced, for example, by applying the above-mentioned adhesive solution to the surface of the release sheet, drying it to form an adhesive layer, and removing the release sheet. be able to. By forming the adhesive layer using an adhesive solution in which the adhesive composition is mixed with a solvent, the dispersibility of the additive (D) in the adhesive layer is as compared with the case where the adhesive is directly applied. Is improved.

Further, the adhesive sheet of the present invention can be produced, for example, by applying the above-mentioned adhesive solution on both sides of a base material and drying to form an adhesive layer.

Further, in the adhesive sheet of the present invention, for example, the above-mentioned adhesive solution is applied to the surface of the release sheet and dried to form an adhesive layer, and a base material is attached to the surface of the adhesive layer. Can be manufactured.

When producing an adhesive sheet in which two or more adhesive layers having the same or different compositions are laminated, for example, an adhesive solution containing an adhesive composition 1 is applied to both sides of a base material and dried to obtain a first method. It is produced by forming an adhesive layer 1, applying an adhesive solution containing an adhesive composition 2 to the surface of the first adhesive layer 1 and drying to form a second adhesive layer 2. be able to. In this case, at least the adhesive composition 2 contains the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D). Above all, it is preferable that both the adhesive compositions 1 and 2 contain the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D).

Further, in the adhesive sheet of the present invention, for example, an adhesive solution containing an adhesive composition 1 is applied to the surface of a release sheet and dried to form an adhesive layer 1, and another adhesive layer 1 is formed on the surface of the adhesive layer 1. It can be produced by applying an adhesive solution containing the adhesive composition 2 and drying to form an adhesive layer 2. In this case, at least one of the adhesive compositions 1 and 2 contains at least the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D). Above all, it is preferable that both the adhesive compositions 1 and 2 contain at least the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C) and filler (D).

The adhesive solution used in the method for producing an adhesive sheet of the present invention contains at least the above-mentioned photocurable resin (A), thermoplastic resin (B), photopolymerization initiator (C), and filler (D). It can be prepared by mixing the agent composition and the solvent. Examples of the solvent used in the adhesive solution include ester solvents such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ketyl ketone, methyl isobutyl ketone, diisobutyl ketone and cyclohexanone; toluene, Examples thereof include aromatic hydrocarbon solvents such as xylene. A dissolver, a butterfly mixer, a BDM twin-screw mixer, a planetary mixer, or the like can be used for mixing the adhesive composition and the solvent.

The method for producing an adhesive sheet of the present invention includes a drying step for removing the solvent after applying the adhesive solution. The drying step is preferably performed at a temperature of about 40 ° C. to 120 ° C., more preferably about 50 ° C. to 90 ° C. This is because the progress of the curing reaction of the adhesive sheet before light irradiation can be suppressed, and the foaming of the sheet surface due to the rapid volatilization of the solvent or the like can be suppressed.

(4) Applications The adhesive sheet of the present invention can be used without being limited by the light transmission of the member. Therefore, the members to be joined using the adhesive sheet of the present invention may or may not have light transmission. Above all, the adhesive sheet of the present invention can be suitably used for joining members having low light transmission or light-impermeable members. As described above, the adhesive sheet of the present invention has a slow curing reaction rate after light irradiation and can have flexibility even after light irradiation. Therefore, by irradiating the adhesive sheet with light in advance when joining the members, the curing reaction proceeds without irradiating the adhesive sheet with light through the members, and the members can be firmly joined. Here, the member (adhesive body) preferably has a light transmittance of 90% or less in the wavelength region of 200 nm to 780 nm, and among them, the transmittance is 80% or less, 70% or less, 60% or less, 50% or less. Is preferable. Further, the light-impermeable member means a member having a light transmittance of 0% in the above wavelength region. The light transmittance of the adherend (member) is a value measured by an ultraviolet-visible spectrophotometer such as V-570 manufactured by JASCO Corporation.

Further, the adhesive sheet of the present invention can be used without being limited by the heat resistance of the member. Therefore, the members to be joined using the adhesive sheet of the present invention may or may not have heat resistance. As described above, the adhesive sheet of the present invention undergoes a curing reaction by light irradiation and has flexibility even after light irradiation, so that the curing reaction proceeds without heating or pressurizing at a high temperature. In addition, in order to accelerate the curing reaction, light irradiation and heat treatment may be used in combination as the curing means, and the above member has heat resistance capable of withstanding the heating temperature of the heat treatment performed for promoting the curing reaction after light irradiation. It is preferable to have.

The adhesive sheet of the present invention is suitably used for dicing processing applications. In other words, the adhesive sheet of the present invention is a laminate produced by dicing, specifically, a laminate in which members are arranged on one side or both sides of the adhesive sheet and the members are solidified by dicing. It can be suitably used for manufacturing or manufacturing a laminate in which a plurality of members are multifaceted on at least one surface of an adhesive sheet. Examples of the laminate in which the members are multifaceted include parts used in an image display device and a laminate in which semiconductor wafers are multifaceted.

Examples of image display devices include mobile terminals (PDAs) such as personal computers, mobile phones, smartphones, and tablet PCs, game machines, televisions (TVs), car navigation systems, touch panels, pen tablets, LCDs, PDPs or ELs, organic ELs, and micros. Examples thereof include an image display device using an image display panel equipped with an LED, a quantum dot (QD), and a large-scale image display device used for industrial use and advertising use. Further, examples of the parts used in the image display device include an image display panel, a circuit board, a rear cover, a bezel, a frame, a chassis, a semiconductor chip, a reinforcing member of a panel made of aluminum and carbon fiber resin, and the like.

2. Laminated body The laminated body of the present invention comprises the adhesive sheet described in the above section "1. Adhesive sheet", the first member bonded to the first main surface of the adhesive sheet, and the adhesive sheet. It has a second member bonded to the second main surface.

In the laminated body of the present invention, the adhesive layer of the adhesive sheet is cured. That is, in the laminated body of the present invention, the first member and the second member are joined by the adhesive layer after the curing of the adhesive sheet. In other words, the first member and the second member are joined by the cured product layer of the adhesive composition according to the above section "1. Adhesive sheet".

According to the laminated body of the present invention, since the first and second members are joined via the adhesive sheet described in the above section "1. Adhesive sheet", the members are hard to peel off and have a high delamination force. In addition, it is possible to suppress the occurrence of burrs, interface peeling, etc. by dicing.

In the laminated body of the present invention, the first member is bonded to the first main surface of the adhesive sheet described in the section of "1. Adhesive sheet" and faces the first main surface of the adhesive sheet. The number of the first and second members is not limited as long as the second member is bonded to the second main surface. That is, in the laminate of the present invention, even if one first member is bonded to the first main surface of the adhesive sheet and one second member is bonded to the second main surface of the adhesive sheet. Often, one first member may be attached to the first main surface of the adhesive sheet and the plurality of second members may be the second main surface of the adhesive sheet. Member may be bonded to the first main surface of the adhesive sheet, and a plurality of second members may be attached to the second main surface of the adhesive sheet.

Above all, in the laminated body of the present invention, it is preferable that at least one of the first member and the second member is bonded to the adhesive sheet in a plurality. This is because it is possible to form a laminated body in which the members are multifaceted, and the effect of using the above-mentioned adhesive sheet when individualizing by dicing is more exhibited.

The member in the laminated body of the present invention may or may not have light transmission. The light transmittance of the member having low light transmittance is as described in the above section "1. Adhesive sheet". Further, the member may or may not have heat resistance, but it is preferable that the member has heat resistance that can withstand the heating temperature of the heat treatment performed for promoting the curing reaction after light irradiation.

Further, in the laminated body of the present invention, when the adhesive layer contains an inorganic filler exhibiting basicity, at least one of the first member and the second member contains a metal surface on the adhesion surface. This makes it possible to suppress corrosion of the metal surface in addition to suppressing the occurrence of burrs and interface peeling due to dicing.

The member including a metal surface on the adherend surface is not particularly limited, and examples thereof include a substrate and a wiring board having metal wiring on one surface of the substrate. In particular, in the case of a wiring board having a patterned metal wiring, where the surface has uneven steps due to the wiring pattern and other members, in the laminated body of the present invention, the adhesive sheet can follow and adhere to such surface steps. Therefore, the wiring board and other members can be firmly joined, and the metal wiring is less likely to be corroded, so that deterioration of the function as the wiring board can be suppressed for a long period of time.

The laminate of the present invention is preferably used in an image display device, and more preferably used in the manufacture of constituent members of the image display device. Examples of the image display device include mobile terminals (PDAs) such as personal computers, mobile phones, smartphones and tablet PCs, game machines, televisions (TVs), car navigation systems, touch panels, pen tablets and the like, LCDs, PDPs or ELs, organic ELs, etc. An image display device using an image display panel equipped with a micro LED, a quantum dot (QD), or the like can be mentioned. Examples of the constituent members of the image display device include an image display panel, a circuit board, a rear cover, a bezel, a frame, a chassis, and a semiconductor chip.

3. 3. Method for Manufacturing Laminated Body The method for manufacturing a laminated body of the present invention is a method for manufacturing a laminated body using the adhesive sheet described in the above section "1. Adhesive sheet", and is used on the first main surface of the adhesive sheet. A step of bonding the first member [1], a step of bonding the second member to the second main surface of the adhesive sheet [2], and a step of curing the adhesive layer of the adhesive sheet [ 3], and further, before the step [1], or during the steps [1] and [2], the first main surface or the second main surface of the adhesive sheet. It has a step of irradiating the active energy ray (hereinafter, may be referred to as a step [0]).

If the adhesive sheet in the present invention is the adhesive sheet of the above-described aspect (I), the first and second main surfaces of the adhesive sheet are the two outermost surfaces of the single-layer or multi-layer adhesive layer facing each other. To say. Further, if the adhesive sheet in the present invention is the adhesive sheet of the above-mentioned aspect (II), the first and second main surfaces of the adhesive sheet are the first adhesive of the adhesive sheet of the aspect (II), respectively. The surface on the layer side and the surface on the second adhesive layer side.

In the above step [1], it is preferable that the first member is pressure-bonded to the first main surface of the adhesive sheet. Further, in the above step [2], it is preferable that the second member is crimped and bonded to the second main surface of the adhesive sheet. By crimping and bonding the member to the adhesive sheet, the adhesive sheet is formed. Since the adherend surface of the member makes it easier to follow and the adhesion between the adhesive sheet and the member can be improved, the bonding force between the first member and the second member via the adhesive layer after curing is further enhanced. Because.

In the above steps [1] and [2], the pressure at which the member is crimped to the adhesive sheet can be in the range of 0.1 to 3000 KPa, preferably in the range of 0.5 to 1000 kPa. , Preferably in the range of 1.0 to 500 kPa. By crimping within the above range, the member can be bonded to the adhesive sheet without being damaged, and the adhesion required for obtaining high bonding strength can be obtained.

In the above steps [1] and [2], the member may be pressure-bonded to the adhesive sheet while heating. By crimping while heating, when the members are joined to each other via the adhesive sheet, they are more firmly adhered to each other, and high joining strength can be obtained. The heating temperature can be set within a range in which the member is not deformed due to damage to the member or strain is generated between the members, and cracks are not generated between the joining material and the member, preferably 150 ° C. or lower and 120 ° C. Hereinafter, it can be 100 ° C. or lower, 80 ° C. or lower, 70 ° C. or lower. By setting the upper limit of the heating temperature, it is possible to suppress damage to the members, deform the members due to strain between the members, and suppress the occurrence of cracks between the adhesive sheet and the members. The heating temperature can be preferably 5 ° C. or higher, 10 ° C. or higher, 20 ° C. or higher, 30 ° C. or higher, and 40 ° C. or higher. This is because setting the lower limit of the heating temperature improves the followability of the adhesive sheet to the adherend surface. The crimping time is not particularly limited as long as it can sufficiently follow and adhere to the adherend surface of the member.

The above step [3] may involve heat treatment. In the production method of the present invention, since the curing reaction of the adhesive sheet is started by irradiating with active energy rays, the curing proceeds even at room temperature, but the above-mentioned adhesion is carried out by performing the above-mentioned step [3] while heating. This is because when the members are bonded to each other via the sheet, the curing reaction can be promoted and a high bonding strength can be obtained in a shorter time.

When the heat treatment is performed in the above step [3], the heating conditions are within a range in which the members are not deformed due to damage to the members to be laminated or strain is generated between the members, or cracks are not generated between the adhesive sheet and the members. It can be set with. The heating temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, further preferably 100 ° C. or lower, and most preferably 80 ° C. or lower in order to prevent damage to the members to be laminated and deformation and flow of the bonding material. ..

In the above step [3], it is preferable to proceed the curing reaction so that the adhesive layer after curing shows the gel fraction described in the above section "1. Adhesive sheet".

The step of irradiating the first main surface or the second main surface of the adhesive sheet with active energy rays (step [0]) can be performed before the step [1]. In this case, the steps [1] and [2] are preferably performed within 24 hours, more preferably 12 hours, and further within 3 hours after the step [0] is performed. It is preferable to carry out within 1 hour, because when the adhesive sheet is attached to the member, it adheres more firmly and high bonding strength can be obtained.

Further, the step [0] may be performed between the steps [1] and [2]. In this case, the step [2] is preferably performed within 24 hours, more preferably within 12 hours, further preferably within 3 hours, and within 1 hour after the step [0] is performed. This is most preferable because when the adhesive sheet is attached to the member, it adheres more firmly and high bonding strength can be obtained.

As the active energy ray, ultraviolet rays, visible light and the like are preferably used, and among them, ultraviolet rays are preferably used. The ultraviolet rays may be irradiated in an atmosphere of an inert gas such as nitrogen gas or in an air atmosphere in order to efficiently carry out the curing reaction by the ultraviolet rays. Further, if necessary, heat may be used in combination as an energy source, irradiated with light, and then heated.

Further, the light to be irradiated preferably has a wavelength region capable of activating the photopolymerization initiator, and it is particularly preferable to use an active energy ray having a wavelength of 300 nm or more and 420 nm or less.

Examples of light sources for irradiating active energy rays include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, electrodeless lamps (fusion lamps), chemical lamps, black light lamps, xenon lamps, and mercury-. Examples thereof include xenon lamps, short arc lamps, helium / cadmium lasers, argon lasers, sunlight, LEDs, sterilization lamps, carbon arcs, scanning type, curtain type electron beam accelerators and the like. Further, a xenon-flash lamp capable of flashing light is preferable because the influence of heat can be minimized.

Irradiation intensity of the active energy ray is preferably 0.1~1000mW / cm ^2, more preferably 0.5～800MW, more preferably 0.1~400mW / cm ^2. The irradiation time of the active energy rays is preferably 1 to 60 seconds, more preferably 5 to 50 seconds, and even more preferably 10 to 40 seconds. By setting the irradiation intensity and time within the above ranges, the heat generated when the activation energy rays are irradiated can be reduced, so that the curing rate after the irradiation with the active energy rays can be suitably adjusted. ..

The irradiation of the active energy rays may be performed once or may be divided into a plurality of times.

Specific examples of the laminated body that can be produced according to the present invention include the specific examples described in the above section “2. Laminated body”.

4. Method for manufacturing an article The method for producing an article of the present invention is a method for producing an article using the adhesive sheet described in the above section "1. Adhesive sheet", and the first main surface of the adhesive sheet is the first. The step of laminating the members [1], the step of laminating the second member on the second main surface of the adhesive sheet [2], and the curing of the adhesive layer of the adhesive sheet to form a laminate. A step [3] of cutting the laminate and a step [4] of cutting the laminate into a plurality of articles, and further before the step [1], or the steps [1] and the above steps. During [2], there is a step of irradiating the first main surface or the second main surface of the adhesive sheet with active energy rays.

According to the method for producing an article of the present invention, since the adhesive sheet described in the above section "1. Adhesive sheet" is used, the generation of burrs can be suppressed in the step [4], that is, the dicing (cutting) step. ..

The steps [1] to [3] in the method for manufacturing an article of the present invention are the same as the steps [1] to [3] described in the above-mentioned section "3. Method for manufacturing a laminate". The description in is omitted.

In the step [4], a known method can be used as a method for cutting the laminate, and examples thereof include blade dicing, laser dicing, plasma dicing, and braking. Further, the cutting (dicing) device used in the step [4] is not particularly limited, and conventionally known devices can be used.

The article produced by the method for producing an article of the present invention is not particularly limited, and examples thereof include a semiconductor wafer chip and an image display member.

The present disclosure is not limited to the above embodiments. The above-described embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present disclosure and exhibiting the same effect and effect is the present invention. Included in the technical scope of the disclosure.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

1. 1. Synthesis example of thermoplastic resin (B) <Preparation of polyurethane (B-1)>
In a reaction vessel, 50.3 parts by mass of an aromatic polyester polyol having a number average molecular weight of 1300 obtained by reacting a 2 mol addition of ethylene oxide of bisphenol A, phthalic acid and adipic acid, 1,6-hexanediol and dodecane were added. 1. 8 parts by mass and 8 parts by mass were mixed and heated to 100 ° C. under reduced pressure conditions to dehydrate until the water content reached 0.05% by mass to obtain the mixture (1).

Next, the mixture (1) cooled to 70 ° C. and 7.9 parts by mass of 4,4'-diphenylmethane diisocyanate are mixed, and then the temperature is raised to 100 ° C. to make the hydroxyl group content constant. Polyurethane (B-1) was obtained by reacting for 3 hours. The polyurethane (B-1) has a hydroxyl group as a polymerizable functional group.

<Preparation of polyurethane (B-2)>
In a reaction vessel, 50.3 parts by mass of an aromatic polyester polyol having a number average molecular weight of 1300 obtained by reacting 2 mol of ethylene oxide of bisphenol A, phthalic acid and adipic acid, 1,6-hexanediol and dodecane 1. 8 parts by mass and 8 parts by mass were mixed and heated to 100 ° C. under reduced pressure conditions to dehydrate until the water content reached 0.05% by mass to obtain the mixture (2).

Next, the mixture (2) cooled to 70 ° C., 4.3 parts by mass of 4,4'-diphenylmethane diisocyanate and 4.3 parts by mass of 2,4'-diphenylmethane diisocyanate were mixed. After that, the temperature was raised to 100 ° C., and the reaction was carried out for 5 hours until the hydroxyl group content became constant to obtain polyurethane (B-2). The polyurethane (B-2) has a hydroxyl group as a polymerizable functional group.

<Preparation of polyurethane (B-3)>
In a reaction vessel, 60 parts by mass of an aliphatic polycarbonate polyol having a number average molecular weight of 2000 obtained by reacting 1,5-pentanediol, 1,6-hexanediol and dialkyl carbonate, and 1,4-butanediol and adipic acid are added. 20 parts by mass of a polyester polyol having a number average molecular weight of 1000 obtained by the reaction is mixed and heated to 100 ° C. under reduced pressure conditions to dehydrate the mixture until the water content reaches 0.05% by mass (3). ) Was obtained.

Next, the mixture (3) cooled to 70 ° C. and 20 parts by mass of dicyclohexylmethane-4,4'-diisocyanate are mixed, then heated to 100 ° C. and reacted for 3 hours to form an isocyanate group. A urethane prepolymer having the above was obtained. 100 parts by mass of the urethane prepolymer was heated and melted at 100 ° C., 11.4 parts by mass of 2-hydroxyethyl acrylate and 0.01 parts by mass of stannous octylate were mixed, and NCO% was increased at 100 ° C. Polyurethane (B-3) was obtained by reacting until it became constant. The polyurethane (B-3) had a polymerizable unsaturated double bond as a polymerizable functional group, and the isocyanate group content (NCO%) was 0% by mass.

(Example 1)
33 parts by mass of the polyurethane (B-1), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel Co., Ltd.), 45 parts by mass of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC Co., Ltd.) By mass, 1.6 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), and calcium bicarbonate particles (“BF-200” manufactured by Shiraishi Calcium), average 40 parts by mass of particle size 5 μm) was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (a-1).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (a-1) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (a-1). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Example 2)
43 parts by mass of the polyurethane (B-2), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel Co., Ltd.), 35 parts by mass of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC Co., Ltd.) Parts by mass, 2.0 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), and calcium bicarbonate particles (“BF-200” manufactured by Shiraishi Calcium), average An adhesive solution containing the adhesive composition (a-2) was obtained by mixing and stirring 13.3 parts by mass (particle size 5 μm) and adding methyl ethyl ketone to adjust the non-volatile content to 75% by mass.

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (a-2) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (a-2). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Example 3)
43 parts by mass of the polyurethane (B-2), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel), 35 parts of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC) By mass, 2.0 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), hydrophobic silica particles (“Silohobic 603” manufactured by Fuji Silicia, average) The particle size was 6.7 μm) 10.0 parts by mass was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (a-3).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (a-3) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (a-3). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Example 4)
33 parts by mass of the polyurethane (B-1), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel Co., Ltd.), 45 parts by mass of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC Co., Ltd.) By mass, 1.6 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), and calcium bicarbonate particles (“BF-200” manufactured by Shiraishi Calcium), average 6 parts by mass of particle size 5 μm) was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (a-4).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (a-4) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (a-4). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Example 5)
58 parts by mass of the polyurethane (B-1), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel), 20 parts by mass of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC) 20 Parts by mass, 2.0 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), and calcium bicarbonate particles (“BF-200” manufactured by Shiraishi Calcium), average 60 parts by mass of particle size 5 μm) was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (a-5).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (a-5) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (a-5). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Comparative Example 1)
43 parts by mass of polyurethane (B-2), 22 parts by mass of alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel Corporation), 35 parts by cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC Corporation) Mix and stir 1.0 part by mass and 1.0 part by mass of a sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro Co., Ltd., solid content concentration 50%), and add methyl ethyl ketone so that the non-volatile content becomes 75% by mass. By adjusting, an adhesive solution containing the adhesive composition (b-1) was obtained.

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (b-1) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a coated layer of the adhesive composition (b-1). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Comparative Example 2)
43 parts by mass of the polyurethane (B-2), 22 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel Co., Ltd.), 35 parts by mass of a cresol novolac type epoxy resin (“N-685-EXP-S” manufactured by DIC Co., Ltd.) Parts by mass, 2.0 parts by mass of sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro, solid content concentration 50%), and calcium bicarbonate particles (“BF-200” manufactured by Shiraishi Calcium), average 190 parts by mass of particle size 5 μm) was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (b-2).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (b-2) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to form a coating layer of the adhesive composition (b-2). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

(Comparative Example 3)
100 parts by mass of the urethane resin (B-3), 43 parts by mass of an alicyclic epoxy resin (“CEL-2021P” manufactured by Daicel), a sulfonium salt-based photocationic polymerization initiator (“CPI-100P” manufactured by San-Apro), solid 11.4 parts by mass (separate concentration 50%) was mixed and stirred, and methyl ethyl ketone was added to adjust the non-volatile content to 75% by mass to obtain an adhesive solution containing the adhesive composition (b-3).

Next, on the surface of the release liner A (one side of a polyethylene terephthalate film having a thickness of 50 μm is peeled with a silicone compound), an adhesive solution containing the above-mentioned adhesive composition (b-3) is applied to a rod-shaped metal. Using an applicator, the film was coated so that the thickness after drying was 150 μm, and the film was put into a dryer at 85 ° C. for 5 minutes and dried to form a coating layer of the adhesive composition (b-3). ..

Further, three coating layers are laminated and laminated to form a multi-layer adhesive layer having a thickness of 450 μm having a release liner A on one surface, and a release liner B is formed on the other surface of the adhesive layer. (One side of a polyethylene terephthalate film having a thickness of 38 μm was peeled off with a silicone compound) was bonded to obtain an adhesive sheet having a total thickness of 450 μm (excluding the thickness of the peeling liner).

3. 3. Evaluation [Initial adhesive strength after application]
The adhesive sheets obtained in Examples and Comparative Examples were cut into a size of 10 mm in width × 10 mm in length and used as a test sample. One of the release liners of the above test sample is removed, and an aluminum plate (light opaque material) with a smooth surface of width 15 mm × length 150 mm × thickness 0.05 mm is placed at 0.05 MPa in a temperature environment of 23 ° C. Press-crimped with pressure for 10 seconds and bonded to obtain a patch. This patch was left to stand in a temperature environment of 23 ° C. for 60 minutes, and then irradiated with ultraviolet rays having ^{an intensity of 300 mW / cm 2 for 15 seconds using an air-cooled mercury lamp (manufactured by Eye Graphics Co., Ltd.).} At this time, the above ultraviolet irradiation was performed without removing the release liner.

The affixed material after irradiation with ultraviolet rays was left to stand in a temperature environment of 23 ° C. for 10 minutes, then the release liner was removed, and an aluminum plate having a smooth surface (width 15 mm × length 150 mm × thickness 0.05 mm) (light opaque). The material) was press-pressed for 10 minutes in a state of being pressurized at 1.0 MPa using a hot pressing device heated to 80 ° C. to obtain a laminate.

The laminated body after press crimping was left to heat at 80 ° C. for 1 hour, left to stand for 30 minutes or more in an environment of 23 ° C. and cooled, and used as a test sample. The shear adhesive force [MPa] of the test sample was determined by performing a tensile test in the 180 degree direction at a tensile speed of 50 mm / min.

[Volume ratio of filler (D) in the adhesive sheet]
For the volume ratio of the filler (D) in the adhesive sheet, the volume of the filler (D) is calculated from the value obtained by dividing the content weight of the filler (D) in the adhesive layer by the specific gravity of the filler (D). The value was calculated by dividing the value by the volume of the adhesive layer.

[Tension breaking elongation]
The adhesive sheets obtained in Examples and Comparative Examples were cut into a size of 10 mm in width × 150 mm in length, and a test piece having a length between marked lines of 50 mm was used as a test piece (for JIS K7127-1999 test piece type 2). Compliant). Next, the test piece was irradiated with ultraviolet rays having ^{an intensity of 300 mW / cm 2} for 15 seconds using an air-cooled mercury lamp (manufactured by Eye Graphics). At this time, the above ultraviolet irradiation was performed without removing the release liner. The pasted product after irradiation with ultraviolet rays was heated and left at 80 ° C. for 3 hours, and then left for 30 minutes or more in an environment of 23 ° C. and cooled, and used as an evaluation sample.

The tensile elongation at break at 25 ° C. of the evaluation sample was measured using a tensile tester under the condition of a tensile speed of 300 mm / min. The measurement was carried out by a method in accordance with JIS K7127-1999 [Plastic-Test method for tensile properties-Part 3: Test conditions for film and sheet].

[Appropriate dicing]
The adhesive sheets obtained in Examples and Comparative Examples were cut into a size of 80 mm in width × 120 mm in length. Next, one of the release liners of the cut adhesive sheet was removed, and a CFRP plate (plain weave, epoxy resin type) having a width of 80 mm, a length of 120 mm, and a thickness of 1.5 mm was placed on a CFRP plate (plain weave, epoxy resin type) at a temperature environment of 80 ° C. and 0.05 MPa. It was pressed and crimped for 30 seconds at the same pressure as above, and bonded.

The patch was left in a temperature environment of 23 ° C. for 60 minutes, and then irradiated with ultraviolet rays having an intensity of 300 mW / cm2 for 15 seconds using an air-cooled mercury lamp (manufactured by Eye Graphics). At this time, the above ultraviolet irradiation was performed without removing the release liner.

The pasted product after irradiation with ultraviolet rays was left to stand in a temperature environment of 23 ° C. for 10 minutes, then the release liner was removed, and the paste was heated to 80 ° C. on a blue plate glass plate having a width of 80 mm, a length of 120 mm and a thickness of 0.5 mm. It was press-pressed for 10 minutes while being pressurized at 1.0 MPa using a hot press device.

The laminate after press crimping was left to heat at 80 ° C. for 1 hour, and left to cool in an environment of 23 ° C. for 30 minutes or more, and used as a test sample. Next, it was cut into a size of 60 mm × 100 mm in width using a dicing saw (manufactured by Disco Corporation, trade name “DAD-522”). ZH05-SD4000-N1-70-BB (manufactured by Disco Corporation) was used for the blade, and the conditions were a blade height of 90 μm, a blade rotation speed of 40,000 rpm, and a dicing speed of 40 mm / sec.

The cross section of the test sample after dicing was observed using a digital microscope VHX-7000 (manufactured by KEYENCE). Four corners after dicing were observed, and the dicing property was evaluated according to the following criteria. ◎ and 〇 were allowed.
(evaluation)
⊚: No burrs of 5 μm or more were observed from the cross section.
◯: Burrs of 5 μm or more and less than 10 μm were observed from the cross section.
▲: Burrs of 10 μm or more were observed from the cross section.
X: The glass was peeled off from the adhesive layer and the glass was broken.

[Followability after irradiation with active energy rays (step followability when a force is applied to the bending or unevenness of the surface of the adherend of the adhesive sheet after UV irradiation)]
The adhesive sheets obtained in Examples and Comparative Examples were cut into 5 cm × 5 cm pieces to obtain test pieces. Next, one of the release sheets of the test piece was peeled off, and pressed and pressure-bonded to the center of a release liner having a thickness of 50 μm cut into 7 cm × 7 cm at a pressure of 0.05 MPa for 10 seconds in a temperature environment of 23 ° C. I matched it. The patch was left in a temperature environment of 23 ° C. for 60 minutes, and then irradiated with ultraviolet rays having an intensity of 100 mW / cm2 for 10 seconds using an electrodeless lamp (fusion lamp H bulb). The pasted product after irradiation with ultraviolet rays was left to stand in a temperature environment of 23 ° C. for 10 minutes, and then press-molded for 10 seconds in a state of being pressurized at 0.5 MPa using a hot press device heated to 80 ° C. Percentage of change in the thickness of the adhesive sheet after hot pressing with respect to the thickness of the adhesive sheet before hot pressing (0.45 mm) (thickness of adhesive sheet after hot pressing / thickness of adhesive sheet before hot pressing) Was evaluated according to the following criteria.
(standard)
◯: The ratio of the thickness of the adhesive sheet after hot pressing to the thickness of the adhesive sheet before hot pressing was less than 90%.
X: The ratio of the thickness of the adhesive sheet after being left to the thickness of the adhesive sheet before being left was 90% or more and less than 100% (no change).

The evaluation results are shown in the table below.

The adhesive sheets of Examples 1 to 5 in which the content of the filler (D) was within a predetermined range had good followability after irradiation with active energy rays and also had good dicing suitability. On the other hand, the adhesive sheet of Comparative Example 1 containing no filler (D) and the adhesive sheet of Comparative Example 2 in which the content of the filler (D) exceeds a predetermined range are affected by burrs and adherends after dicing. The peeling of the adhesive layer was confirmed. Further, a photocurable resin (A) having a polymerizable functional group other than the polymerizable unsaturated double bond, a thermoplastic resin (B) having a polymerizable functional group other than the polymerizable unsaturated double bond, and photopolymerization initiation. The adhesive sheet of Comparative Example 3 which did not contain the agent (C) at the same time had poor followability after irradiation with active energy rays.

The adhesive sheets obtained in the examples were cut into sizes of 50 mm in width and 50 mm in length as test samples, and the dispersibility of the filler (D) in the sheets was evaluated when observed with an optical microscope. In the adhesive sheet obtained in the examples, there was less than one agglomerate derived from the filler (D) exceeding 1000 μm, and the dispersibility of the filler (D) in the adhesive sheet was good. On the other hand, as a reference example, when preparing the adhesive solution in Examples 1 to 5, a solvent-free liquid adhesive was used without adding methyl ethyl ketone, and the liquid adhesive was heated to 100 ° C. After that, it hangs directly on the release liner B (one side of a 38 μm thick polyethylene terephthalate film is peeled off with a silicone compound), covers it with a release liner, and presses the liquid adhesive until it reaches a thickness of 450 μm. It was crushed to prepare an adhesive sheet. When the dispersibility of the adhesive sheet was evaluated in the same manner, three or more agglomerates derived from the filler (D) exceeding 1000 μm were confirmed, and the filler (D) was compared with the adhesive sheet obtained in Examples. Poor dispersibility.

Claims (14)

A photocurable resin (A) having a polymerizable functional group other than a polymerizable unsaturated double bond,
A thermoplastic resin (B) having a polymerizable functional group other than a polymerizable unsaturated double bond,
Photopolymerization initiator (C) and
Filler (D) and
With an adhesive layer containing
An adhesive sheet in which the content of the filler (D) in the adhesive layer is 5% by mass or more and 45% by mass or less. The adhesive sheet according to claim 1, wherein the average particle size of the filler (D) is 0.5 μm or more and 100 μm or less. The adhesive sheet according to claim 1 or 2, which contains at least one of calcium carbonate particles and silica particles as the filler (D). The adhesive sheet according to any one of claims 1 to 3, wherein the thickness of the adhesive layer is 10 μm or more and 3000 μm or less. The adhesive sheet according to any one of claims 1 to 4, wherein the filler (D) is dispersed in the adhesive layer. The adhesive sheet according to any one of claims 1 to 5, wherein the photocurable resin (A) has a photocationically polymerizable and / or a photoanionic polymerizable functional group. The adhesion according to any one of claims 1 to 6, wherein the thermoplastic resin (B) has at least one polymerizable functional group selected from the group consisting of an isocyanate group, a hydroxyl group, an oxetanyl group and an epoxy group. Sheet. The adhesive sheet according to any one of claims 1 to 7, wherein the thermoplastic resin (B) is a urethane resin. The adhesive sheet according to any one of claims 1 to 8, wherein the photopolymerization initiator (C) is a photocationic polymerization initiator. The adhesive sheet according to any one of claims 1 to 9, which is used for dicing processing. The adhesive sheet according to any one of claims 1 to 10, the first member bonded to the first main surface of the adhesive sheet, and the second main surface of the adhesive sheet are bonded to each other. A laminated body having a second member and the like. The laminate according to claim 11, which is used in an image display device. A method for producing a laminate using the adhesive sheet according to any one of claims 1 to 10.
The step [1] of attaching the first member to the first main surface of the adhesive sheet, and
In the step [2] of attaching the second member to the second main surface of the adhesive sheet,
The step [3] of curing the adhesive layer of the adhesive sheet is provided.
Further, before the step [1], or during the steps [1] and [2], the first main surface or the second main surface of the adhesive sheet is irradiated with active energy rays. A method for producing a laminate, which comprises a step of making a laminate. A method for manufacturing an article using the adhesive sheet according to any one of claims 1 to 10.
The step [1] of attaching the first member to the first main surface of the adhesive sheet, and
In the step [2] of attaching the second member to the second main surface of the adhesive sheet,
The step [3] of curing the adhesive layer of the adhesive sheet to form a laminate,
The step [4] of cutting the laminate and individualizing it into a plurality of articles.
Have,
Further, before the step [1], or during the steps [1] and [2], the first main surface or the second main surface of the adhesive sheet is irradiated with active energy rays. A method of manufacturing an article, which comprises a step of making an article.